The recent defection of some elders in the church certainly underlined the need for care in selecting replacements. But frankly, whether defection is involved or not, in the best of circumstances this process involves risks. The apostle urges thoroughness so that the risks might be minimized. Prior to the laying on of hands, the ceremony in which the elders signaled before the congregation God's choice of a new elder (4:14; compare Acts 13:3), the leadership of the church must thoroughly examine the candidate. To judge from the bishop/elder code in chapter 3, which Paul gave for this purpose, evidence of Christian lifestyle, not just correct doctrine, was essential.
The issue in verse 22 is sin or tendencies that lead to sin, and a sloppy assessment will implicate the examiner or examining committee in the leader's sin. Consequently, if the well-being of the church is not enough to ensure careful attention to the process, the thought of personally sharing in the sin of another is added. This concept of sharing in the sin of another (whether by tacit approval or by apathetic failure to take a stand) rests on an important theological premise. We might call this a "theology of separation," though we must develop it with balance. God called his people to be separate from the sinful nations, where separation had geographical and religious implications (Is 52:11; Jer 51:45; Rev 18:4), and that call was fundamental to the formation of Israel (Gen 12:1). In the New Testament the concept of separation develops into the dialectical call to be "in the world but not of the world" (Jn 17:15-18; 1 Cor 5:9-11). Separation now calls the believer and the church to resist conformity with the world not by a physical withdrawal from it, which would make mission impossible, but rather by a spiritual transformation that brings an understanding of God's will and prepares one for critical evaluation of the world's thoughts and ways (Rom 12:2; 1 Jn 2:15-17). The implications of conformity are serious not simply for the church's well-being but for its standing before God. Revelation 18:4 suggests that conformity with the world is not only unfortunate but culpable, for it will lead to judgment. Equally grave is the careless appointment to the church's leadership of one whose sin ought to have meant disqualification, or turning a blind eye or tolerating sin that is later discovered in a leader.
In view of this theological background, it should be unthinkable that the leadership of a church would be indifferent to sin among its leaders. It is also not possible for the leaders to wash their hands of the sins of one they have placed into office. By laying on hands, they willingly identify with that one's sin. In the concluding exhortation to purity, Paul rephrases and abbreviates this theology of separation that underlies the verse.
But in the Ephesian church pure, as a description of Christian living, had various connotations. To the false teachers it meant asceticism, including abstinence from certain foods (4:3). Whatever benefits abstinence might have for the believer, the heretics had taken it to a sinful extreme. Not only is Timothy to distance himself from these false views, but he is, for the sake of his health, to demonstrate Christian freedom and drink wine instead of exclusively water (5:23).
Paul's conclusion to this passage on the selection of elders has a proverbial ring, appealing to common sense. This popular wisdom emphasizes the two advantages of a thorough examination of leader candidates. First, some who are unfit to lead the church disqualify themselves from the start with obvious sins. But the disqualifying sins of others, who are equally unfit, come to light only after extensive scrutiny (v. 24)--thus Paul's instructions.
Second, the marks of genuine faith (good deeds; compare 3:2-7) that point toward eligibility may be immediately evident in some people. But in the case of other qualified people, perhaps of quieter temperament, careful searching will be needed to recognize their potential (v. 25)--yet another reason for heeding Paul's advice.
The importance of the church's leadership has already been well illustrated in this letter. A leader's influence in the community is inevitable. But will it be for good or for ill? Clearly both possibilities exist. Some of the risks can be minimized when leaders are selected. Quick decisions based on cursory evaluations have no place in this process.