If the faces are triangles (2 triangles) and use no more then 4 vertices yes.
In edit mode, editting tab, under mesh tools, very bottom. Join Trigangles. This creates one 2 poly face or a square (Rectangle) You can select your entire creation and do this.
Don't like the change? Ctrl T does the oposite.
Also, if your problem is a loop cut, select the loopcut by Ctrl Right Mouse Click, and delete it with X, 7.
Otherwise you have to do it the slow and long way.
