I forgave someone a year ago, but I still have these random moments in which I feel some anger. What is my next step here?
When we forgive, the anger does not necessarily go away completely. This does not necessarily imply that you have not forgiven. Are you in control of that anger or is the anger controlling you? You say the anger comes “randomly.” How often does this happen? If it occurs infrequently, say once a month, then I think you have forgiven and are experiencing the natural and imperfect parts of being hurt and forgiving. If the anger is more intense and comes more frequently, say once a week, then I recommend going back through the forgiveness process with this person.
For additional information, see What is Forgiveness?