The Bible uses the word “leaven” twenty-four times. It is used in the Old Testament eleven times. Five of these times it gives instruction about the observance of the Passover (Ex. 12:15, 19; 13:7; 34:25; Deut. 16:4). Four times it is used to forbid the use of leaven with a grain offering (Lev. 2:11; 6:17; 10:12). Amos mentions it being offered with sacrifices as an illustration of how far the Jews had drifted from honoring God (Amos 4:5). The other time it is mentioned is where God commanded using leaven with the bread offered at Pentecost (Lev. 16:27). It is always used in a literal way in the Old Testament.
However, when one comes to the New Testament, the picture is entirely different. Every reference to it has a spiritual, figurative application. Look at the following usages.
The church is like leaven (Matt. 13: 33; Luke 13:21). This is the only time that leaven is used in a good sense in the New Testament. Leaven placed in dough spreads throughout the dough and amazingly increases the size of the loaf. Jesus wanted His disciples to visualize the growth of the church.
False teaching is like leaven (Matt. 16:6, 11-12; Mark 8:15). When the Lord first spoke of the leaven of the Pharisees and the Sadducees, His disciples did not understand. Afterwards, they discovered that He was speaking of the false teachings of men and how dangerous it is in spreading to others. Paul also describes false teachers as being like leaven which will permeate the entire church (Gal. 5:9).
Hypocrisy is like leaven (Luke 12:1). It was not just the doctrine of the Pharisees that Jesus rebuked, but also the fact that what they first appeared to be was, in reality, a lie. When Christians are hypocrites, their influence leads to hypocrisy in others. This concept is also found in Paul’s uses of the phrase “the leaven of malice and wickedness” and contrasts it with sincerity and truth (1 Cor. 5:8)
Sin left unattended in the church is like leaven (1 Cor. 5:6-7). The church at Corinth had serious problems. Paul described an immoral situation which was so vile even the pagans would not practice it. Yet, it was in the church, and instead of dealing with it, they were proud. Paul warned them that if this sin and all sins were not addressed, it would spread to all the church just like leaven. He told them to purge out that evil leaven and give that man back to Satan. Oh, that the church today would heed his words!
Leaven and you. The fact leaven is used to describe the church shows the power of righteousness. It is used to describe the power of unrighteousness. The question to be considered is, what kind of leavening influence are you having?