In today's Gospel reading from Mark 6, Jesus taught his disciples the Our Father. Then he added, "If you forgive men their transgressions, your heavenly Father will forgive you. But if you do not forgive men, neither will your Father forgive your transgressions." Straight and clear speaking. It comes down to whether you want God to be lenient with you or not.
If there are men who have transgressed against you, then you pray for them. This may be extremely hard, so I suggest that you don't think of them as your personal enemies, but as sinners in general ~ they simply offended God as you did. Besides, Jesus commanded us to love our enemies ~ what beautiful teaching this is! If you can forgive all your transgressors from your heart, you will receive absolute peace and great joy for obeying and glorifying God! This reward alone is worth the work.