A red letter parable with an answer to why evil is allowed to prosper. God is merciful. Even when we are weak and immature he protects us against the ultimate consequence of evil in our midst.

Matthew 13:27-30

And the servants of the master of the house came and said to him, ‘Master, did you not sow good seed in your field? How then does it have weeds?’

He said to them, ‘An enemy has done this.’ So the servants said to him, ‘Then do you want us to go and gather them?’

But he said, ‘No, lest in gathering the weeds you root up the wheat along with them.

Let both grow together until the harvest, and at harvest time I will tell the reapers, “Gather the weeds first and bind them in bundles to be burned, but gather the wheat into my barn.”’”

Bible Gateway link: Matthew 13:27-30 (ESV)