Luke 13:20–21 (NKJV)
20 And again He said, “To what shall I liken the kingdom of God? 21 It is like leaven, which a woman took and hid in three measures of meal till it was all leavened.”
For several weeks, we have been explaining some of the traditions that we include in our corporate worship. Last week we touched upon our practice of celebrating the Lord’s Supper weekly; this week let us consider our practice of using leavened bread in the Lord’s Supper. Why use yeast? Why leavened bread?
Given that the Lord’s Supper has parallels with the old covenant rite of Passover, some have argued that Christians should use unleavened bread in the Supper. Passover was the last day in the Feast of Unleavened Bread, given to celebrate the exodus from Egypt. Since the Lord’s Supper was inaugurated during that feast, some have argued that we should use unleavened bread in our celebration. What should we think of this?
Let us say, first, that there is nothing wrong with a church deciding to use unleavened bread in its celebration of the Supper. “The kingdom of God is not in eating and drinking but in righteousness, peace, and joy in the Holy Spirit” (Rom 14:17). Further, Paul exhorts us in Corinthians, “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” (1 Cor 5:8). Unleavened bread can be used to convey such an exhortation and there is nothing wrong in its use.
That said, throughout Scripture both leavened and unleavened bread were used in sacred rites. While unleavened bread was used at Passover, leavened bread was used for the peace offerings (Lev 7:13) as well as for the celebration of Pentecost (Lev 23:16-17). Given that the Lord’s Supper is the new covenant feast that centers all these rites in Christ’s death and resurrection, it is important to recall why unleavened bread was used at Passover to determine if that rationale applies to the Lord’s Supper.

According to Exodus 12, unleavened bread highlighted the “haste” with which our fathers were to leave Egypt. God wanted them to leave quickly and so they didn’t have time for the yeast to rise. This sense of haste was confirmed by their dress – they were to eat the meal prepared to travel. “And thus you shall eat it: with a belt on your waste, your sandals on your feet, and your staff in your hand. So you shall eat it in haste” (Ex 12:11).
So does the Lord’s Supper commemorate this same sense of “haste”? I don’t think so. The only haste seen at the Last Supper is that of Judas who is told, “What you have to do, do quickly!” That is hardly the type of haste we want to imitate! So what does the bread of the Lord’s Supper commemorate? It commemorates the sacrifice of Jesus’ body and the commencement of His kingdom. At the Supper Jesus took bread and broke it; He then shared it among his disciples, saying, “Take, eat, this is My body.” The bread points not to haste but to Christ.
And this brings us back to the parable I read earlier. And again [Jesus] said, “To what shall I liken the kingdom of God? It is like leaven, which a woman took and hid in three measures of meal till it was all leavened.” Jesus uses leaven to illustrate the pervasive influence of His kingdom, His rule. His kingdom shall operate in the world like leaven, slowly, organically permeating the world until the entire earth is leavened. And it is this characteristic of Christ’s rule that we are attempting to emphasize by using leavened bread: Jesus’ kingdom is like leaven. Slowly, organically the reality symbolized by this bread will become realized throughout the world. Jesus will spread His rule throughout the nations of the earth.

The use of leavened bread, therefore, summons us to be like leaven, to be instruments of God’s work in our families, communities, and workplaces. We are so to live and labor that the entire loaf becomes leavened. Reminded that God has called us to be leaven; to live so that through our witness Christ’s rule on earth is established; let us confess that we often fail to live in this leavening fashion. And as you are able, let us kneel together as we do so. We will have a time of silent confession followed by the corporate confession found in your bulletin.