Your question is too vague.
The appropriate gearing will depend on your ability and the nature of the terrain you like to ride.
I ride the California desert a lot and prefer lower gearing (less speed, more torque) for climbing the hills and really technical stuff. But that gearing sucks when you get to a power line road or a long sand wash and your buddies are leaving you in the dust.
Some of my buddies, who are much better riders than I am, gear their bikes the opposite: their first gear is more like my second. But they manage to fly through the stuff that I have to pick my way through.
Tell us what issues you are having and then maybe we can recommend a gearing change that will help.
Rod