Please help me!!

I adopted a 5 year old male cat about a month ago. He is really sweet but he hides under the bed all day long. If we don't take him out he will only come out to use the bath room and eat. When we do take him out he is the sweetest thing in the world and he'll hang out with us for hours until we leave the room. But he will never come out on his own to hang out with us. I do have 2 other cats but they don't seem to be bothering him. What can i do?
Thanks

Leave him be. Seriously if you know he is healthy, just ignore him as far as paying attention to him. feed him, see to his immediate needs, but leave him completely alone. That doesn't mean starve him, deprive him of water or not change his litter pans, but just ignore him in all other aspects. Don't keep pulling him out of his hiding spot. He is scared, and the more you approach him the worse he will get. Put him on a schedule- food at x amount of times every day, water changed same time every day, litterpans scooped out same time every day. Go into the room where he is hiding, sit on the floor, read out loud to him softly for a few minutes every day- leave treats in your imprint on the floor- keep the room quiet, the lights low, he will come out when he wants to and not before

Yes. In other words, work with him as with a shy cat - which he is...
There are many threads about work with ex homeless semiferal shy cats. Look in these and take ideas - the most important Hissy told already.

Good you have own friendly cats. It should make this whole a little easier.