Galatians 5:9

A little leaven leavens the whole mass.

1 Corinthians 15:33

Be not deceived: Evil communications corrupt good manners.

Matthew 16:6-12

And Jesus said to them: Take heed and be ware of the leaven of the Pharisees and Sadducees.

Matthew 23:33

Serpents, generation of vipers, how can you escape the condemnation of hell?

Mark 8:15

And he charged them, saying: Take heed, and beware of the leaven of the Pharisees, and of the leaven of Herod.

Luke 12:1

In the mean time, when myriads of the people had come together, so that they trod one upon another, he began to say to his disciples first of all: Beware of the leaven of the Pharisees, which is hypocrisy.

Luke 13:21

It is like leaven, which a woman took and hid in three measures of flour, till the whole was leavened.

1 Corinthians 5:6-7

Your boasting is not good; know you not that a little leaven leavens the whole mass?

2 Timothy 2:17

and their word will eat as a gangrene: of whom are Hyrnenaeus and Philetus,

Treasury of Scripture Knowledge

Summary

A little leaven leaveneth the whole lump.

Bible References

General references

Matthew 23:33
Serpents, generation of vipers, how can you escape the condemnation of hell?
Matthew 16:6
And Jesus said to them: Take heed and be ware of the leaven of the Pharisees and Sadducees.
Mark 8:15
And he charged them, saying: Take heed, and beware of the leaven of the Pharisees, and of the leaven of Herod.
Luke 12:1
In the mean time, when myriads of the people had come together, so that they trod one upon another, he began to say to his disciples first of all: Beware of the leaven of the Pharisees, which is hypocrisy.
Luke 13:21
It is like leaven, which a woman took and hid in three measures of flour, till the whole was leavened.
1 Corinthians 5:6
Your boasting is not good; know you not that a little leaven leavens the whole mass?
1 Corinthians 15:33
Be not deceived: Evil communications corrupt good manners.
2 Timothy 2:17
and their word will eat as a gangrene: of whom are Hyrnenaeus and Philetus,