He was not a God to start with. Just an old-fashioned heavy. Being begotten by top god ZEUS with ALCMENA did not automatically bestow godly status. After all, ZEUS did put himself around a lot. (For all you know, you might be a descendent of the King of Olympus too. Register an immortality claim and see what happens.)
Being a god son was not much fun. HERA detested most of ZEUS’s extra-marital kids, but she hated this one with a divine vengeance and plotted the most evil plots against him, even before he was born. (See EURYSTHEUS.)
HERACLES means ‘Hera’s Glory’, but after she drove him insane and forced him to kill his own children it was more like Hera’s Gory.
Poor Herc, reeling from the murder of his children, went to the Oracle of APOLLO for psychological counseling and was told that a bit of physical labor would take his mind off things. Thus began The Labors Of Heracles.
These tasks, in truth devised by HERA and implemented by his arch enemy and rival EURYSTHEUS, lasted many years — and were designed solely for the purpose of wiping him out. But he didn’t know that. "Complete those Labors and immortality shall be yours," the Oracle had said, and poor Herc didn’t know any better.
So he went off and battled monsters, cut heads off things, stole Golden Delicious apples and had adventures which were far too exciting to be related here... while EURYSTHEUS taunted him and tricked him and cooked up devious schemes to trouble him.
Although HERACLES succeeded in every quest, this only made HERA hate him the more. The poor guy traveled everywhere doing his best to right wrongs, but she plagued him with storms and evilness for many years afterwards. Finally, after many more adventures, including being sold as a slave, becoming a pirate and fighting for OLYMPUS against the giant sons of the TITANS, he died in a mix-up over a magic potion, and was accidentally tainted with the blood of the HYDRA from one of his own arrowheads.
But as a reward for all his trials and tribulations, he was offered a grudging kind of immortality and a share of the film rights. Reconciled to HERA at last, he married her daughter HEBE and now lives happily ever after. And then did it all over again for the Romans under the name HERCULES...