I believe that Allah forgives those who repent and return back to Him... even his sins are as big like the seas....
so why we humans don't try to forgive and let those guys who had 'pasts' bury it in the past and move forward to changing a better life,,, and I believe that as long as he started to fear Allah and do good deeds(prayer,sunna,etc), he finds a good Muslima who will support, give a chance, believe, trust him, then, he will succeed. InshaAllah. But then, if he finds one who will not believe him and would always criticize him, then he may not make it(A'udhubillah)... rather, he would search again for a better pious woman.
"The whole world is a provision, and the best object of benefit of the world is the pious woman." as Prophet Muhammad sallalahu alayhi wasallam stated.
This pious woman will help him, they, together will build a place in Jannah inshaAllah.