If you are out of fellowship, confess your sin. Get back on track. The only place were we can become free from the slavery of malice, hatred and grudges is in fellowship with our Lord. By being in the center of God's will we can have a life of freedom. If we allow sin to control us we are in slavery.
Sin eats the soul.
Life is too short. We cannot afford to bear grudges. Time is too short. The stake is too high. If we hold ill will long enough it might secure such a hold upon us that we will take it right into the casket with us.