Removing leaven is a physical symbol of the spiritual process of removing sin. Yeast, like sin, multiplies rapidly and spreads like a contagion. Here are some points to consider:

• Purge out malice and wickedness (1 Corinthians 5:7-8). These are general terms for evil, the opposite of God's will. "This is leaven that sours the mind to a great degree," wrote Matthew Henry in his commentary on these verses.
• Watch out for the leaven of hypocrisy (Luke 12:1). Some crumbs are well hidden from others (and even from ourselves), but to God there is nothing "hidden that will not be known" (Luke 12:2). David asked God to "cleanse me from secret faults" (Psalm 19:12).
• Paul warned of the attitudes that would be widespread in the last days (2 Timothy 3:1-5). Are any "crumbs" of self-love, pride, unthankfulness, etc., lurking in our "home"? Galatians 5:19-21 also lists the works of the flesh, the attitudes and actions we too easily become infected with.
• Replace these things with the spiritual unleavened bread of sincerity and truth (1 Corinthians 5:8). Galatians 5:22-23 lists the fruit of the Spirit.