To Atone or not to Atone

I think atonement for past sins is definitely possible. Most times it can take a long time to atone sins, and it depends on how severe they may be. One time I said something bad about one of my friends and she found out and was furious with me. It made me feel bad about what I said and I told her that I was extremely sorry, but I knew that it would take more than just my words to prove to her that I was sorry. It took a long time for her to forgive me and I had to prove through my actions that I was worth forgiving, she wouldn’t just take my word for it. It takes a lot of time to heal the hurt caused by sins.