I'm torn.
On the one hand, I've played lots of fiery-smitey clerics, and I really enjoy them.
On the other, the more flashy combat spells you give the cleric, the more you blur the difference between the cleric and the wizard. And that very easily--not automatically, but almost--to the CoDzilla issue. If a cleric can be just as good a blaster as a wizard, and can wear armor and has better HP and BAB--then unless a game is remarkably non-combat-centered, the wizard becomes an absolutely inferior option in any/all mechanical and effectiveness measurements.
So even if one doesn't strip away all the overt/flashy combat spells from the cleric, one does need to A) seriously limit their number, and B) make them notably less effective than arcane spells of the same level.
Of course, one could instead balance it by giving wizards some other massive advantage, beyond their spells, but that risks taking the class outside the bounds of what most D&D players expect. Doesn't mean it can't be done, of course.
(And all this leaves aside the flavor issue. A lot of people, myself included, want arcane and divine magic to feel different. One of the only ways to do that is to have a relatively firm line of demarcation between what one or the other can do.)