[This is from my other blogs, but I figured I'd put it here too. Just to heavy things up a bit. It's my tiniest version of my "But predestination!" post. The short version with more memes and quotes and information can be found here, and the longest version (a series of posts full of many more Calvinist comments, my Calvinist ex-pastor's sermons, and my replies to them, written for my own amusement and for my ex-church) can be found by starting here. But this tiny version includes only the most basic parts you need to know, with a few memes and quotes thrown in to spice it up.]
At the heart of Calvinism is predestination and God's sovereignty (among other things, like "total depravity"), which according to Calvinism essentially amounts to: "God preplans and controls everything, even sin and evil and all our decisions, and so He pre-picks who goes to heaven and who goes to hell. He causes the 'elect' to believe in Him and be saved, but He made sure the 'non-elect' have no chance or ability to believe and be saved because He predetermined they'd go to hell (and so Jesus never died for them anyway), all for His glory."