Bearing grudges as believers shouldn't be our attitude. We should be willing to forgive people no matter the what the case may be. We should always project Christ as our role model in everything we do. Our question in every situation before we take any action is what would Christ do? Jesus instructed that we forgive people.
It all begins with loving people. Jesus said that we should love our enemies. When we love even our enemies we love let go of every weight we hold against anyone. If we don't forgive then we are not setting a good example to others out there. When we identify as christians we should be aware that the whole world would be watching us and the things we do.
We don't do the way people of the world do. If people don't forgive then we are not in any way different from others. No one is perfect. We too ourselves may have offended people one way or the other. It is almost impossible that we live our lives perfectly. Loving people is one of the hardest thing to do on earth. Most people do not know what love truly is that is why when offenses come they find it difficult to forgive.
But true love is unconditional. It's what prompts us to forgive even when people really hurt us. This is what our heavenly Father expects us to do as His children.
Forgive with all your heart