It's also important to note that you don't need religion to be charitable or help other people.
There isn't a single "good" that church does to other people that couldn't be done by secular means.
It's not a tax. You can't get your passport revoked if you don't pay tithing. You won't go to jail for tax evasion, either. In fact, probably nothing will happen. You can continue to go to church every Sunday without paying tithing and most congregations would still welcome you with open arms. Ecclesiastical leaders might remind you that tithing requires faith and that you would receive more blessings if you paid your tithe, but as long as said leaders do not profit from said tithes, I don't see a problem with it as there is no conflict of interest.
is key.
Right, and you don't need a running club to motivate you to run or a school to help you learn. But for a lot of people, they sure do help if being charitable/running/learning is your goal.