Do not be overcome by evil, but overcome evil with good. (Romans 12:21 ESV)
In this verse, we are told not to be acted upon (do not be overcome) by evil, but rather we are to act upon (overcome) evil by doing good.
This is an important aspect of the sanctification of believers. We are to actively weed out the evil that remains within us, confessing our sins as we go, rather than hope to drift toward holiness, which just doesn’t happen. Our faith is to be active, not passive. Passivity is the breeding ground for evil.
It has been this way since the beginning. The concept of actively working against your own sin was first recorded as God spoke to Cain, prior to the first murder.
The LORD said to Cain, “Why are you angry, and why has your face fallen? If you do well, will you not be accepted? And if you do not do well, sin is crouching at the door. Its desire is for you, but you must rule over it.” (Genesis 4:6-7 ESV)