Whatever we do or don't believe, repentance is something which we must all address many times in this life. We are not perfect. We will err. It is important for us to address what we do wrong. We must make as much as practically possible those we harm whole.
The story of the Scroll of Jonah provides us with four ideas regarding repentance.
First, No one should begrudge G-d's love, care, and forgiveness to anyone else. This is true even if we don't much care for them.
Second, It is not possible to run away from G-d's presence. In the context of this article, that is important. We also cannot run away from the consequences of our own actions. We do need to repent. Both for those we harmed, and from the harm we do ourselves.
Third, G-d takes pity on all creatures. Can or should we do less? It starts with ourselves. We can learn to be accepting of our flaws, while still addressing them. We are not and never will be perfect. We are all perfectible. We can always improve.
Finally, G-d is always ready and eager to accept our repentance. All that is holding things up is our not repenting. Time to get into an action mode here.
I have presented ideas from the Scroll of Jonah. Please feel free to present your original ideas, and quotations from such literature, devotional or otherwise, that moves you on this topic.