Something that I really struggle with is holding grudges and not letting things go. When someone says something that hurts me or makes me super upset, I hold it against them. The other day I was thinking back to things that have happened when I was like 12, and I realized I am still holding grudges to things that happened to me 6 years ago. I just can't seem to let the things go.
In Ephesians 4:31-32 it says "Let all bitterness and wrath and anger and clamor and slander be put away from you, along with all malice. Be kind to one another, tenderhearted, forgiving one another, as God in Christ forgave you."
I haven't completed been able to let everything go, and it definitely is going to be a process for me, but in this verse it says God forgave us. We have done so many horrible things to him, and yet he still forgives us and loves us. If God can forgive us, we should be able to forgive one another.