If you're convince that he is truly sorry and ready to stay, welcome him back. You don't have to give them that special place in your heart anymore but welcome them back at least as a casual friend.
If you still love the person and feeling sure that they can fill the void in your life, let them in, but be more careful not to repeat the same mistake twice. And be honest to each other, don't hide the love you have for each other, express them to erase doubts. Moreover, we never got forever to tell the ones we love how much we care or to spend time with them. If you don't love him anymore, let him know where he stands as well.
Those are my thoughts, but it's what your heart tells you that should be more important. If you doubt your inner voice, pray and listen again, it would say something that would help you decide finally on what you need to do. Goodluck.
PattiWinner