You will be able to forgive others as soon as you are ready to accept forgiveness for yourself. The things we do not forgive in others are the same things we refuse to forgive in ourselves. Alternatively, as soon as you are ready to receive grace into your greatest shame, you will be able to offer the same to another. If you can be forgiven then so can I, and vice versa. Grace reaches both of us at the same time; it is the great equalizer.