I have 3 blks & 3 whts 1 red in box trying to hook up light with blk wht and ground can anybody help?

I am trying to change light fixture and there are 3 black wires, 3 white wires, one red and 3 ground (which I am uming there are 3 different wires coming into the box) the fixture I am putting in only has a black white and ground. How would I connect all these wires?