What should I do about this guy?

Ok, so I really need help on this. There's this guy that asked me out and he's really cute. I said yes but then all my friends were telling me he cheats on girls and he's a jerk and he thinks he's better than everyone. So I told him I just wanted to be friends but maybe we could get to know eachother a little better. So last night he called me and was telling me everything. I asked him if he had ever cheated on a girl and he said know but if he did, he would tell me. And turns out he's had a pretty rough life and he said all the people that were telling me everything just hated him from 2 years ago and that he's changed but no one would talk to him anymore so they can't see how he's changed. Everyone was telling me I need to not go out with him and everything like that. But, he seems like a really sweet guy and he told me he only has his little sister left to live for. Only a few people told me I should go out with him and that was the people that actually hang out with him. I don't want people to think I'm gullible and everything, but I want to give him a chance. This one girl said "everyone around you right now has so much respect for you,but if you date him, we're not gonna have any respect for you." But = just don't know what to do. Should me and him just date secretly? Please help.