In your first scripture, Jesus was talking about the devil giving his children gifts, but then won't Jesus give his children even more.
Evil is evil is evil, God told me one time, you can cast a demon out of someone, but you can't bring them to christ , like a unsaved person. People try to christianize magic or Halloween, but God says that anything from the devil is evil and to have nothing to do with it or you are a enemy of Christ. Some people think that just because you know Jesus, like Catholics, that they are going to heaven, but God said, is Satan going to heaven? NO and he knows Christ. Many say they are christians, but deal in idolotry, fornication, magic, sorcery, horiscopes, necromancer, praying to the sun, moon, and the stars, go to psychics, believe that it is by works instead of grace that we are saved. Add or take away from the bible, pray to a stature with out ears that can't hear or eyes that cannot see, pray to dead saints, ony Jesus died and rose again, all the saints are in the ground. The only way to get to the Father it says in the bible is though Jesus Christ, no mother mary, or the rosary, purgatory. That is why there is so many religions, christianity means following the teachings of Christ, not dead religious rituals that are repitious. Even mormans, jehovia witnesses, and catholics want to call themselves christians, but they add and take away form the bible and the last scripture in the book says if you add or take away, yo wil not enter the kingdom of God. I think I will call myself a child of Christ.
So to answer your question, sin can be forgiven, but evil can not. What is Jesus going to do to satan in the end, and God says evil is an abomination, detestable, and you cannot change evil because it comes from satan and satan is evil and God is good.
God Bless you.