I wanted to know if it is OK to use ceiling paint as a primer on my wall that was just spackled?

Nope... sorry.

A primer and ceiling paint simply are not the same thing.

I used to think a primer was not necessary as well... then I saw the difference between a wall that was primed and one that was not primed... WOW! What a difference.

The idea here is that a primer seals the wall board and the plaster or joint compound so that when paint is finally applied it will lay down on the wall without absorbing into the wall at different rates over the wall board and the plaster or joint compound. That is, you will not have spotting and odd reflections when sun hits certain spots.

Hope that helped some. Of course, others will chime in on this soon, I am sure.. so wait until you hear from them as well... but result is a better job is achieved with a primer!

Have good day... MARK