Q: #171. What is the significance of leaven/yeast in the Bible?
By: Steve Shirley
A: Whenever leaven is mentioned in the Bible (22 times in the Old Testament and 17 times in the New Testament), it always (or almost always) represents sin or evil. The first instance in which this word is used is found in (Ex 12:15). This was just before the Passover, in which God destroyed all of the firstborn of Egypt, but spared the firstborn of Israel in the last of the 10 plagues that He visited upon Egypt.
God gave instructions to Moses and Aaron that they were command Israel to celebrate this Passover each year "throughout your generations" with a feast. This feast, called the "Feast of Unleavened Bread" followed the Passover day (the 14th day of the 1st month on the Jewish calendar). It lasted 7 days. During the first day of this week, they were commanded to remove all leaven from their houses. In addition, they were not to eat any bread which contained leaven for the whole week.
Just as most things in the Old Testament point to Jesus, the "unleavened bread" does as well. In the New Testament, Jesus referred to Himself as the "Bread of Life" (Jn 6:22-59). He was, of course, also without sin (1 Jn 3:5)(2 Cor 5:21)(Heb 4:15)(1 Pet 2:22). Because leaven is equated with sin throughout the Bible, the "unleavened bread" pictured bread (Jesus) without sin in it. In addition, a "blood sacrifice" (the blood also represented Jesus in the Old Testament: Heb 9:11-28, Heb 10:11-25) was not to be offered with leavened bread (Ex 23:18)(Ex 34:25).
It is interesting to note, however, that for a peace offering (Lev 7:13) and wave offering (Lev 23:17) God commanded that leaven be used.
In the New Testament, we have 5 more examples of the symbolism of leaven. Before sharing these examples, I should first explain why the use of leaven in these examples gives us a good picture of sin. Leaven/yeast is basically old, fermented dough that is placed in new dough to make it rise. The key is that you only need to add a very small amount of fermented dough to make new dough rise. (Gal 5:9) describes this saying, "a little leaven leaveneth the whole lump."
Carrying this out to sin, it can be said that "a little sin can wind up destroying the whole body." This body can be symbolic of our individual body or the larger body of Christ (i.e. the Church). I believe a good parallel to this can be seen above, where on the 1st day of the Feast of Unleavened Bread, God commanded that all leaven (sin) should be cleaned out of the house. As Christians, our bodies are the "house" or Temple of God, and we are told not to "defile" God's Temple with sin (1 Cor 3:16-17), but rather, we are to "glorify God in our body" (1 Cor 6:19-20).
Jesus gave us the first 4 symbolic examples of leaven in the New Testament. In the first, Jesus compares the Kingdom of Heaven/God to leaven (Mt 13:33)(Lk 13:20-21). There is great debate amongst scholars as to whether the use of leaven in this example is positive or negative. Some believe that it is positively speaking of the "rise" or growth of the gospel in the world or a person's life. Others believe that it is negatively speaking of evil doctrine working its way into the kingdom.
In the second instance, Jesus compared the false teaching (sin) of the Pharisees and Sadducees with leaven (Mt 16:6-12).
In the third, Jesus warned of the leaven of Herod (he was evil and immoral: Mt 4:1-12, Mk 6:14-29, Lk 3:18-21, Lk 23:7-12) and again the Pharisees (Mk 8:15).
In the fourth, Jesus said, "Beware of the leaven of the Pharisees which is hypocrisy" (sin) (Lk 12:1).
Finally, Paul gives us a very clear final example in (1 Cor 5). In this case, a man is living in incest with his father's wife, and those in the church are proud of this! Paul uses the same words that he previously used in (Gal 5:9) saying, "a little leaven leaveneth the whole lump." He warned the church to "remove this man from your midst" (1 Cor 5:2) and "remove this wicked man from amongst yourselves" (1 Cor 5:13). He also said such a person should be "judged" (1 Cor 5:12).
The reason for this is because if one person is allowed to continue in unrepentant sin (we all sin, but as Christians we are sorry for it), it will soon affect the rest of the body (the whole lump). In (1 Cor 5:8), Paul also gives us a great contrast between leavened (sin) and unleavened (sin free) bread, comparing leaven with "malice and wickedness" and unleavened bread with "sincerity and truth."
In (1 Cor 5:9-13), Paul closes the chapter with one of the most sober (and difficult) warnings in the Bible for Christians. He warns Christians to not even "associate" with a "brother" who is practicing unrepentant sin. (Paul makes a distinction between a Christian "brother" and a person who is not a Christian.) Why does Paul issue this warning? It seems clear from the numerous previous warnings that it is because his sin can have a negative impact on either our personal walk with the Lord, or on the church as a whole. Are we heeding this warning as Christians?