Putting sin out of our lives means effectively resisting temptation. We may be tempted to hold a grudge against someone, or to lust after someone. We have to fight these temptations in our minds. We have to put thoughts of lust or thoughts of hatred out of our minds.
But though we put these thoughts out, often they pop back into our minds just as quick, over and over. And over time they can wear us out. We begin putting these thoughts out more slowly till we don't put them out at all.
But if we put wrong thoughts out, we have to put right thoughts into our minds. We have to redirect our minds towards right thoughts. We cannot leave a vacuum in our minds. Trying to be neutral about something by not thinking about it at all doesn't always work.
God commands, not that we just refrain from hating our enemies, but that we actively love them.
"But I say to you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who spitefully use you and persecute you" (Matthew 5:44).
So if you find yourself resenting someone, try praying for that person. Ask God to bless that person. Try to think of something you can do for that person. Do that every time thoughts of resentment come into your mind. Ask God to help that person make it into the kingdom of God.
Here is another example. Suppose you find yourself attracted to the wife of another man. She is beautiful in face, in form, and in personality. You can't stop thinking about her and desiring her. Yet, God says, "You shall not covet your neighbor’s house; you shall not covet your neighbor’s wife, nor his male servant, nor his female servant, nor his ox, nor his donkey, nor anything that is your neighbor’s" (Exodus 20:17).
You try putting thoughts about her out of your mind, but those thoughts keep coming back. She is beautiful, and you can't ignore it.
Try this. Everything you think of her, give God thanks in prayer on behalf of her husband that God has given him such a beautiful and charming wife. Pray that God will bless their marriage more and more. Pray that they will be happy together, and thank God for their happiness. And pray that God will help the husband appreciate and enjoy to the full his wife's beauty and charm.
In this way, you can replace wrong thoughts with right ones.
That is one of the lessons of unleavened bread. We put sin out, but we also put righteousness in.
Being neutral doesn't work.