Sin is wheneve you do something wrong, if you cheat on a test, you have commited a sin, you kill or insult or rape someone, that is sin. I must agree with MSP (wow, this is probably the first time I agreed with him ever) in that there are severities of sins, EVERYONE MAKES MISTAKES, and supposedly god understands this, so if you just steal a persons pencil or cheat on a test it can be forgiven, but if you kill or rape someone, unforgivable.