Oh yes. I loved using flaming sphere with my first D&D character. It wasn't always very efficient (despite a 18 Ints, saving throws are so easily succeeded!), but it has managed to help considerably often. Among other, non-directly-destructive uses of that damage spell, it allowed to prevent enemies from flanking an ally ("you want to flank my buddy, you have to invade Ms Flaming Sphere's personal space, and she's a bit hot-tempered..."), likewise blocking passageways, and intimidating creatures (like when it made a water elemental flee).
If you want them to better grasp the tactical utility of spells, you can also read them the excerpt of Sep's story hour where Nwm the druid single-handedly slaughter an army with his spells and a magic item. First, entrap the opposition to prevent them from fleeing or counterattacking, then lay down the smackdown. You can't put the cart before the horses, and teamwork (having both an entangling druid and a blasting wizard, for example) just allow to put both in the good order in shorter sequence than you could do alone.
Also, clever use of spell in combat does not necessarily results in the destruction of the enemy. To take a low-level example, the gnome who uses her innate ghost sound ability during a goblin ambush to make the goblins believe there's a squad of dwarves charging at them has a chance to make the goblins flee, freeing the party from an uncomfortable situation. And if the goblins realize they were cheated and decide to come back, they won't have the benefit of surprise nor of good tactical positionning.