So i just adopted a male adult sugar glider from my friend who couldnt take care of it about 2 weeks ago. In the beginning he was so scared and he kept hiding under the paper bedding in his cage and only comes out to eat and drink and occasionally runs around the cage at night. In the daytime when he’s sleeping in his pouch in the cage i’ll try to carry him out but he’ll hiss at me so i let him be. Yesterday however, i managed to carry the pouch out with him inside, but the moment i got the pouch out, he lunged at me and chomped down on my finger (i say chomp because i was bleeding and it still hurts), and the next thing i know he ran off somewhere in my house and i spent the whole day turning my house inside out trying to find him, thank god i found him hidden in one of my boxes and managed to put him back in his cage. Im new to caring for sugar gliders but i know they are not aggressive in nature so im wondering how am i supposed to bond with this little guy because everytime i try to he’ll hiss or crab at me and the only time i ever be able to get close to him is to give him some treats.

What I would do...

take the long road. You are new to glider.. glider is new to you.. and glider sounds new to people's hands.
Get a BIG cage, critternation sized 2feetby3feetby4feet. get a quality running wheel. Put in some foraging cups hanging around cage.
forget about handling him for a few months. start with talking to him at night when you hear him come out. feed him a few treats threw the bars. every other night put a treat in half in foraging cups, 6-8 cups sounds good, so he has to move around cage to get the treats.
Put a shirt the smells like sweaty you and put on cage, make a piece of fleece smell like you and put in sleeping pouch, re-scent it often.
Give him time to get to see and hear you with nothing bad happening (like you trying to eat him). He will crab at you all the time in pouch, its his bark, don't let it bother you.

Our newest glider connor crabs at me, looks at me from in pouch like he is ready to full on attack. I talk to him, he calms down, then I pet the back of his head, he has not bit me yet, but he used to be friendly with his first owner a long time ago.

After some time, maybe months like I said, see if you can open cage door and feed him a treat, give him a pet without getting a hard bite, or a run away. If so I would then move to normal bonding stuff. glider in bonding pouch, play in small dark room, trying to see if he will explore me.