The Holy Spirit is the yeast in the bread? Well, that's a wrong interpretation. In the Scriptures, leaven signifies evil things and evil doctrines. In the Old Testament, leaven was forbidden in the meal offering (Ex. 23:18, 34:25; Lev. 2:11). In the New Testament, Jesus implied it was something negative also. He told the disciples to "beware of the leaven of the Pharisees, which is hypocrisy (Lk. 12:1). Yes, in Matt. 13:33, He said that "The kingdom of the heavens is like leaven, which a woman took and hid in 3 measures of meal until the whole was leavened." But that doesn't mean it was a good thing. The "woman" signifies the church as the practical kingdom of the heavens, with Christ, the unleavened fine flour, as its content. However, even in the early days, believers were leavening in things from their backgrounds, like the law, and Gnostic teachings. The Catholic Church also leavened in a lot of things that were not the "fine flour." The Apostle Paul rebuked the Corinthians, saying, "Your boasting is not good. Do you not know that a little leaven leavens the whole lump?" Then he tells them to purge out the old leaven that they may be a new lump (1 Cor.5:6-7). Besides, the Spirit is typified by olive oil, which is listed as an ingredient in the meal offering. Water is not listed (Lev. 2:4-8).