I consider myself agnostic but I will try to put your mind at ease.
1st: The bible says that god created everything on this earth.
2nd: The story about Adam and Eve eating an apple from the forbidden tree is a story about prohibition if I have ever heard. God prohibited Adam and Eve from eating the apples and not even god himself could stop two people from eating an apple from a tree, if god can't do it then what makes anyone think the government can stop anyone?
3rd: Most of the problems associated with marijuana come from prohibition itself. Prohibition forces people to buy it from the gangs instead of buying it legally. The government is essentially protecting the gangs business by not allowing legal competition.
4th: Marijuana has many legit uses, it increases appetite in cancer and hiv/aids patients. Its a very good muscle relaxant, it can relieve headaches, it helps patients with glaucoma, etc.
5th: It has never killed anyone and it less addictive than coffee.
The only bad thing marijuana does to most people is it makes it ok to be bored, and its when we are bored that we should be doing stuff to improve ourselves like learning guitar or reading, etc.