I am replacing a flourescent light.

[RandyEB]

I am replacing a flourescent light. It had two sets of wires in the ceiling. One is from the junction box and another going to the switch. How do I connect it all?

[markmark]

You should have two black wires going to the light switch (or, it could be a black and a white). The hot wire in the junction box in the ceiling is spliced to one of the wires going to the switch, this wire is the constant hot. The other wire coming from the light switch is the "switch leg", and the switch sends electricity through this wire to your light, which would be spliced to the black wire going to the light fixture ballast. The white wires in the junction box are the neutral wires, and spliced to the white wire going to the light fixture ballast.