Pantheon is was a very underused champion until LCS 2014, when everyone saw his potential because of pro player. He is an AD Caster, which isn't really a carry, but still does good damage. He is one of the best early game lane champions because of his Q poke, and also a very good midgame champion. If played correctly, he won't fall off late game.

Pros: Early game is good
Mid game is phenomenal
Strong harass
Mandrop
He is pantheon


Cons: Late game falls off
cant get at champions inside grass, unless warded
Mana problems have to be solved quickly (solved by blue buff)

Pantheon's main combo is q w e. It brings the enemies hit points down to about 1/2 early game, to about 1/3 mid game and 1/4 or 1/5 late game.
Pantheon's ult combo is r on the enemy while spamming w, because it will make you jump farther, then e q. If the enemy isn't down to 1/2 by then, its probably a good idea to back and heal up, unless a jungler is on the way.

Your spear is good for getting enemy creeps while laneing against a ranged character. However, you have to watch your mana to make sure you don't run out prematurely. When you can, go in and auto attack when the minion is really low.

Pantheon is good for ganks with anyone that stuns, pulls, or slows enemies. That way, pantheon can more or less ult right on top of the enemy. Make sure, however, to ult a little further from where an enemy is slowed or stunned (Not for enemies that are pulled by blitz, thresh, etc.)

Also, Galio Pantheon Ults together are op because if galio and pantheon time correctly, they can destroy squishy champs as well as bring down the tanks to about 1/3 hp.

Pantheon, contrary to popular belief, can actually juke. In some cases, he needs a ward to target, but otherwise, just do the following:
if Top Purple: no decent juke
if Top Blue: e approximately where the ghost is, then stun it and run away.
If Bottom Purple: same as top blue
if Bottom Purple: no decent juke

To juke using the golems, ward the golem area, then stun a golem and run away with free lols (except if that counterjungler is there)