Should I give my friend another chance?

I used to have a really good friend. We became close after the death of a mutual best friend. He was (and still is) dating my best friend and I was (and still am) dating his best friend and all of us were very close with the friend that died. Naturally the four of us all became inseparable. When he broke up and got back together with my friend and dropped out of school I stopped speaking to him. I was disappointed in him for dropping out and I was upset with the way he treated my friend. He was also became very obtrusive and condescending. We haven't spoken in several months. Lately, however, I've begun to miss the friendship that we once had. The one year anniversary of our friend's death is coming up and I have a good opportunity to patch things up with him and I think that that's what my friend would want, but I don't know. Should I forgive and forget or keep him out of my life? I really want to give him another chance to have that friendship back, but I'm afraid that he's changed for good.