Here the apostle exhorts them to purity, by purging out the old leaven. In this observe,
I. The advice itself, addressed either, 1. To the church in general; and so purging out the old leaven, that they might be a new lump, refers to the putting away from themselves that wicked person, 1 Cor. 5:13. Note, Christian churches should be pure and holy, and not bear such corrupt and scandalous members. They are to be unleavened, and should endure no such heterogeneous mixture to sour and corrupt them. Or, 2. To each particular member of the church. And so it implies that they should purge themselves from all impurity of heart and life, especially from this kind of wickedness, to which the Corinthians were addicted to a proverb. See the argument at the beginning. This old leaven was in a particular manner to be purged out, that they might become a new lump. Note, Christians should be careful to keep themselves clean, as well as purge polluted members out of their society. And they should especially avoid the sins to which they themselves were once most addicted, and the reigning vices of the places and the people where they live. They were also to purge themselves from malice and wickedness—all ill-will and mischievous subtlety. This is leaven that sours the mind to a great degree. It is not improbable that this was intended as a check to some who gloried in the scandalous behaviour of the offender, both out of pride and pique. Note, Christians should be careful to keep free from malice and mischief. Love is the very essence and life of the Christian religion. It is the fairest image of God, for God is love (1 John 4:16), and therefore it is no wonder if it be the greatest beauty and ornament of a Christian. But malice is murder in its principles: He that hates his brother is a murderer (1 John 3:15), he bears the image and proclaims him the offspring of him who was a murderer from the beginning, John 8:44. How hateful should every thing be to a Christian that looks like malice and mischief.
II. The reason with which this advice is enforced: For Christ our passover is sacrificed for us, 1 Cor. 5:7. This is the great doctrine of the gospel. The Jews, after they had killed the passover, kept the feast of unleavened bread. So must we; not for seven days only, but all our days. We should die with our Saviour to sin, be planted into the likeness of his death by mortifying sin, and into the likeness of his resurrection by rising again to newness of life, and that internal and external. We must have new hearts and new lives. Note, The whole life of a Christian must be a feast of unleavened bread. His common conversation and his religious performances must be holy. He must purge out the old leaven, and keep the feast of unleavened bread of sincerity and truth. He must be without guilt in his conduct towards God and man. And the more there is of sincerity in our own profession, the less shall we censure that of others. Note, On the whole, The sacrifice of our Redeemer is the strongest argument with a gracious heart for purity and sincerity. How sincere a regard did he show to our welfare, in dying for us! and how terrible a proof was his death of the detestable nature of sin, and God’s displeasure against it! Heinous evil, that could not be expiated but with the blood of the Son of God! And shall a Christian love the murderer of his Lord? God forbid.