ECUMENISM ĕk’ yōō mĕn’ ĭsm (οἰκουμένη, G3876, lit. inhabited world but occasionally has the meaning of cultured world as in contrast to barbarian societies). A theological term dealing with the unity and universality of the Christian faith and the Christian Church.

The mutual concepts of unity and universality are rooted in OT concepts of the covenant and cult worship but come to fullest expression in the NT doctrine of the Church.

1. OT concepts of covenant universality and cultic unity. Ecumenism as both universality and unity are clearly observable in the context of OT Biblical theology. Israelite particularism sometimes obscures the broader concepts of the “world” and “nations” but the evidence clearly points to a profound universalism in the OT. (a) Creation and the genealogical table of nations in Genesis clearly place God’s covenant people within the broader framework of universal world history (cf. Gen 1; 2; 5; 10). (b) The Abrahamic Covenant not only calls attention to Israel’s elective soteriology but includes “all the families of the earth” (Gen 12:1-3; 17:1-8). (c) God’s covenant with Israel at Sinai implies both a redemptive particularism as well as a universal priesthood. Yahweh calls Israel to “be a kingdom of priests and a holy nation” (Exod 19:5, 6). Indeed, the record of OT history portrays Israel’s failure to serve in this servant ministry, as Yahweh’s priestly Qâhâl (congregation) among the Goyim (nations). (d) During the monarchy of David there is a growing consciousness of a universal mission. (Cf. the Davidic Psalms 9:11; 18:49; 57:9.) Even more pronounced is Solomon’s prayer of dedication after the erection of the Temple—that the Temple would become a place of universal worship of Yahweh (1 Kings 8:41-53). (e) The fact that the prophetic lit. consistently contains “foreign nation sections” in which judgment is pronounced upon and salvation is promised to these nations also confirms the deep-seated universalism implicit in the structure of Israel’s faith. (Cf. Amos 1:3-2:3; Isa 13-28; Jer 46:51.) (f) Also one may trace in the exilic and postexilic prophets an equal emphasis upon Israel’s universal mission to the nations. What Israel had failed to be, her diaspora among the kingdoms of the world was to accomplish. (Cf. Jer 18:7; Ezek 3:6; 47:22; Mal 1:11.) (g) Finally, what are we to conclude about the numerous cases of Gentile participation in Israel’s history as well as the examples of faith found among non-Israelites? Note the “mixed multitude” which came out of Egypt with Israel (Exod 12:38); the protection of the “stranger” (Deut 10:19); Rahab the Canaanite harlot in Joshua 2; the whole story of Ruth and her contribution to the Davidic line; Ittai (2 Sam 15:21); and Naaman (2 Kings 5).

This universalism must not hide the equally obvious fact of Israel’s uniqueness and particular election. This particularism is vital and essential to the covenant relationship of Yahweh and Israel: “Now therefore, if you will obey my voice and keep my covenant, you shall be my own possession among all peoples; for all the earth is mine” (Exod 19:5; cf. Deut 7:6-16). The Deuteronomic idea of Yahweh’s choosing a “place where His name will dwell” served during the monarchy to justify the establishment of a central sanctuary where not only Israel but all nations would come to worship. (Cf. Deut 12; 14:23-25; 15:20; 16:1-16; 17:8, 10; 18:6; 23:16; 31:11; esp. 33:27.) History has recorded the elaborate growth of cultic ceremony and ritualism which developed around the Temple. The centralizing of Israel’s worship in Jerusalem was intended to provide the unity of Israel’s covenant relationship with Yahweh. The division of the monarchy in 931 b.c. and the increase in Baalism in both the southern and northern kingdoms indicates the failure of cultic centralization as well as unity based upon a single sanctuary. With the exilic diaspora and the development of the synagogue, Israel had to find her unity in the recovery of that essential spirituality of God’s covenantal relationship; hence, later Judaism turned to the Shema (cf. Deut 6:4-6) as a theological basis for her oneness before God. The debate over a centralized sanctuary never ceased in Judaism, and echoes can still be heard in Jesus’ discussion with the woman at the well in Sychar (cf. John 4).

The concept of unity was vital to OT eschatology. (a) In the prophetic writings there are repeated references to Zion as the source of man’s knowledge of God and salvation. “It shall come to pass in the latter days that the mountain of the house of the Lord shall be established as the highest of the mountains,...and all the nations shall flow to it, and many peoples shall come, and say: ‘Come, let us go up to the mountain of the Lord, to the house of the God of Jacob; that he may teach us his ways and that we may walk in his paths.’ For out of Zion shall go forth the law, and the word of the Lord from Jerusalem” (Isa 2:2, 3; cf. Isa 56:6-8; 66:18-21; Mic 4:1ff.). (b) The apocalyptic vision of the prophet Ezekiel in chs. 40-48 where a new Temple is seen points again to the cult as the center of Israel’s faith, worship and unity. Although Ezekiel warns against “admitting foreigners uncircumcised in heart and flesh” in 44:7, his enlarged vision of the boundaries of the land obviously includes other nations: “You shall allot it as an inheritance for yourselves and for the aliens who reside among you and have begotten children among you. They shall be to you as native-born sons of Israel; with you they shall be allotted an inheritance among the tribes of Israel” (47:21-23). (c) Jeremiah’s prophecy of a “new covenant” engraved on the human heart speaks of a spiritual unity transcending all institutions and legal prescriptions (Jer 31:31-34). It is the same “new covenant” which forms the basis for unity as well as universality in the NT Church as the “body of Christ.” (Cf. Heb 8:8-12; note the textual variants in the institution of the Eucharist in Matt 26:17-29 and Mark 14:12-25; also observe Luke’s a ssociation of the Eucharist with the kingdom and Israel in 22:28-30.) (d) And ultimately, not only the cultic unity of Israel’s worship but in Israel herself—both old and new Israel—as the “people of God,” there is to be seen both continuity and unity (cf. Gal 6:13-16). This can account for the prophetic interpretation of Israel’s return to Pal. as a united kingdom (cf. Jer 31-34; Ezek 36; 37). Paul’s discourse on Israel in Romans 9-11 also points to the continuing role of Israel in God’s Heilsgeschichte, but it is a role in which all nations will also play a part. It is here that eschatology blends with ecumenism as both universality and unity (cf. Rev 7:1-17).

2. The “world-theology” of the NT. In the NT oikoumenē always is interpreted by the more frequent term kosmos. The latter term speaks of a divinely created world of order and humanity, of an ordered society of men, of an organic society controlled by the “evil one” and soteriologically of a world redeemed through Jesus Christ. (Cf. Matt 4:8; 5:14; 26:13; Mark 8:36; John 1:9, 10, 29; 3:16, 17, 19; 4:42; 12:31; Acts 17:24; Rom 1:18, 20; 11:15; 1 Cor 1:20, 21; 2 Cor 5:19; Gal 4:3; 1 John 2:15-17.) Although the longer ending of Mark is of questionable textual authority, there can be no doubt that the mission of the Church is coextensive with the universal redemption of Jesus Christ (cf. Mark 16:15; 2 Cor 5:14-21). Oikoumenē is the kosmos become the kingdom of Christ! (Cf. Rev 11:15.)

3. Ekklēsia as Church-church. The concept of Church-church attempts to indicate two facts about NT ecclesiology: (a) there is a distinction between the Church as a metaphysical spiritual reality transcending all historical institutional forms and the existence of the church as a local institution; and (b) the hyphen connecting Church with church points to the NT teaching that all local congregations depend for their existence upon the metaphysical, spiritual reality of the Church as the “body of Christ.” At the same time, the Church always assumes and manifests itself in the reality of institutional societies who bear a distinctively Christological character. Paul’s Ephesian letter presents the clearest examples of the NT idea of the Church. Speaking of Christ and the Church, Paul says “he has put all things under his feet and has made him the head over all things for the church, which is his body, the fulness of him who fills all in all” (Eph 1:22, 23; cf. Col 1:15-29). The “fulness of him who fills all in all” is not simply Christ but Christ and His Church! (Cf. Eph 2:19-22; 3:1-12; 5:21-33; 2 Cor 12:12, 13; Rom 12:3-8.) That the term ekklēsia in the NT most frequently refers to local congregations is shown by its use in the Book of Acts. (Cf. 8:1; 9:31; 11:22, 26; 12:1; Rom 16:1; 1 Cor 1:2; 1 Thess 1:1.)

Ecumenically speaking the Church transcends all historical, institutional and geographical expressions but is, nevertheless, manifested in all local assemblies called into being by the kerygma of Jesus as the Christ. (Cf. Acts 2:14-47.) The pastoral nature of the NT lit. reveals the tension of the churches always being called to be the Church.

4. Conclusions: unity, universality and institutionalism. (a) Unity: in later Christianity the term “catholic” (καθ̓ ὅλῃ), came to designate both the unity as well as the universality of the Church and is one of the clearest indications that ecumenicity soon became a concern of the post-apostolic church. (Note the third article of the Apostles’ Creed.) The idea of a kath’ holē church is found only in adjectival examples in the NT. (Cf. ἐφ̓ ὅλῃ τὴ̀ν ἐκκλησίαν, Acts 5:11; σὺ̀ν ὅλῃ τῇ ἐκκλησίᾳ, 15:22.) Ignatius (d. a.d. 107) is the first to use the term to distinguish a true church which holds to the apostolic doctrine of Christ from all other institutions founded upon heresy. The NT stress upon unity among Christians is almost too obvious to require illustration. Note, however, Christ’s promise to build “His Church” and the word “church” is sing. (Matt 16:18). Christ’s high-priestly prayer in John 17 to which ecumenics have always appealed is a prayer that the unity of Christians will serve apologetically the spread of the Gospel (vv. 20-26). Earlier in the fourth gospel, Christ is presented as saying “there shall be one flock, one shepherd” (10:16). Paul’s repeated emphasis wherever the Church is defined as the “body of Christ” is upon her essential oneness in Christ. (Cf. 1 Cor 12:12, 13; Rom 12:3-8; Eph 4:1-16.) He answers the schism of the Corinthian church with the rebuke “is Christ divided?” (1 Cor 1:10-17).

(b) Universality: Christ’s great commission is a call to a worldwide mission—“Go into all the world” (Matt 28:19, 20). The nineteen hundred years of church history is confirmation of the church’s ecumenical mission and its partial fulfillment. Yet even in the 1st cent. Paul expresses his “ambition to preach the gospel, not where Christ has already been named,” and he hoped that before his life was over he might travel as far as Spain—considered then to be one of the utmost western points of the world. (Cf. Rom 15:20, 28.) In Acts 1:8, the Church’s mission is coextensive with the “end of the earth.”

(c) Institutionalism: the question of unity and universality have more recently raised the question of a united, universal institution which can lay claim to being “Christ’s Church.” No NT evidence can support any attempt to construct a monolithic institution. There is indeed clear evidence that the Church in the NT period was institutional in nature with a Christological, apostolic foundation, with ministerial offices, with a liturgical structure and with a membership concept capable of ecclesiastical discipline; but there is no evidence that a centralized organization with headquarters in Jerusalem, Antioch or Rome ever existed in the 1st cent. or was projected for future centuries. (Cf. Matt 18:15-20; Acts 2:37-47; 6:1-6; 14:23; 20:17, 28-32; 1 Cor 5:1-13; 10:14-22; 11:17-34; Eph 2:20; 4:1-16; Phil 1:1; 1 Tim 3:1-16; Titus 1:5-9.) The unity of the Early Church and the unity which the Church in all ages is called to demonstrate is her confession of Jesus as Lord and her members as servants for Jesus’ sake. (Cf. 2 Cor 4:1-6.)

“Having sketched the Heilsgeschichte from Abraham to Christ...the early chapters of Genesis which tell of the Creation and the Fall, the Deluge and the Tower of Babel serve to universalize the historical experience of Israel. The strange history of Israel which culminated in Christ and the rise of the Christian Church as the new Israel has significance for the whole world of men who fell in Adam and are all included in the covenant made with Noah....The Bible, then, gives us the record of God’s ways with a particular community, but the story is set in a universal framework....The biblical history became universal history through the emergence of the Church Catholic and it is still in the Church that history in the fullest sense is made, because it is primarily in the Church that man meets with God and makes the response which God demands. It is within the Church that the Bible is read and the Sacraments administered in the context of an act of worship through which believers are made contemporary with the great creative events of history constituting God’s revelation of His will.” (Norman W. Porteous, “Old Testament Theology,” The Old Testament and Modern Study, ed. by H. H. Rowley [1951], 342, 343.)

Bibliography J. H. Maude, “Catholicism, Catholicity,” HERE, III (1928), 258-261; O. J. Baab, The Theology of the Old Testament (1949), 183-186; E. Brunner, The Misunderstanding of the Church (1953); L. Newbigin, The Household of God (1953); J. D. Murch, Co-operation Without Compromise (1956); T. F. Torrance, Conflict and Agreement in the Church, 2 vols. (1959); J. B. Payne, The Theology of the Older Testament (1962); H. Sasse, “κόσμος, G3180, ” TDNT, III (1965), 868-895; K. L. Schmidt, “ἐκκλησία, G1711, ” TDNT, III (1965), 501-536; B. Vassady, Christ’s Church: Evangelical, Catholic, and Reformed (1965); O. Michel “ἡ οἰκουμένη,” TDNT, V (1967), 157-159.