6 Your glorying is not good. Do you not know that a little leaven leavens the whole lump?
7 Therefore purge out the old leaven, that you may be a new lump, since you truly are unleavened. For indeed Christ, our Passover, was sacrificed for us.
8 Therefore let us keep the feast, not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth.
glorying (v.6) — from v.2 — not the boasting itself but their ground for boasting
do you not know (v.6) — They should have known — they were boasting about how wise they were.
little (v.6) — stressed — it only takes a small amount
old leaven (vs. 7 and 8) — spiritual corruption such as malice and wickedness (v.8)
Verse 7 is a reference to Exodus 12:18-20; 13:6-7; the Jewish household was enjoined to remove all leaven in preparation for the Passover. This signalized the complete break with the old manner of life in Egypt, and their entrance upon the new life they were designed to enjoy in fellowship with God. so with an assembly, this fellowship must be maintained in all purity, everything being purged out that may intrude, so that each member, and therefore the whole assembly, may maintain a condition in accordance with the new (that is the unleavened) life in Christ, responding continually to the holy calling wherein we are called. — Vine, page 38.
Christ (v.7) — heavily stressed
passover (v.7) — a metonymy — a substitution of a word for an attribute or concept for that of the thing meant (as in “suit” for businessman)
Since Christ is our Passover Lamb, we should observe the spiritual equivalent of the passover feast. It was required of the people that on the eve of this feast all leaven should be removed from their homes. From that time to the time the paschal lamb was offered in the temple, no leaven was to appear on their tables. This suggests the Christian’s attitude to life. He should exclude all sin, anything leavenous, from his life. Anything that would contaminate the body or the mind or the spirit should be put away. — Laurin, page 108.
The Passover feast of Old Testament times was followed by, or rather expanded into, the feast of Unleavened Bread; i.e., the feast of Unleavened Bread included the foregoing Passover Eve (Exodus 12:15, 17). In preparation for this whole celebration, every vestige of leaven, or yeast, was to be removed from every Hebrew home for one week. Indeed, those who ate leavened bread at that time were to be “cut off” from the people of Israel (Exodus 12:15-20). This is important, for in 1 Corinthians 10:11 the apostle, referring to Israel’s experiences, says: “These were written for our learning and admonition.”
With many Jews still in the Corinthian congregation, the Gentiles doubtless clearly understood the meaning of all this — and so should we.
“Purge out therefore the old leaven,” he says, “that ye may be a new lump, as ye are unleavened.” Is there a contradiction here? If they were unleavened, perfectly cleansed from all evil, why need they “purge out the old leaven“? The answer appears as we continue reading: “Ye are unleavened, for Christ our Passover is sacrificed for us” (v.7).
In Christ, and through His finished work in their behalf, they actually were cleansed from all sin (cf. 6:11), but experientially they must “purge out” all evil from themselves, individually and as an assembly, keeping the feast of Unleavened Bread, as it were, “in sincerity and truth,” with the leaven of the old life carefully “purged out.” — Stam, pages 109-110.
sacrificed (v.7) — tense indicates a past event with ongoing results
feast (v.8) — or “festival” — here used of the spiritual walk (to continue the reference to passover and bread)
malice (v.8) = viciousness
wickedness (v.8) = that which is injurious — Together with “malice” it covers the scope of sin
sincerity (v.8) = purity — having actions align with convictions
truth (v.8) = consistent with reality