James 3:18

And the seed whose fruit is righteousness (spiritual maturity) is sown in peace by those who make peace (by actively encouraging goodwill between individuals). 

Believers should, to the best of their abilities, live in peace with other believers and non-believers. It is hard to grow with God when we are in strife because our focus is wrong.  Love and kindness should be at the center of our hearts.   It may take practice, but God loved us and forgave us, and so should we.