The Templar does get good will and Fort saves, plus mettle. THat's evasion for Fort and Will saves. And WEapon Specilization all at first level. However, as a fighter, you might already have that, and even if not it's easy for fighters to get.
But the spells, turn undead, curing, and domains of the cleric clearly make it supior. Plus no need to wast way to many skill points on Knowledge religion or a feat on Endurance. If you find you really like the spell power of the cleric you can advance to awsome power, but the templar is much more limited there.