Like I said to Vinny on another thread, proof beyond a reasonable doubt. That works well enough to send someone to prison for the rest of their life, so it should be good enough to establish a religion as absolutely true. Basically I need to be convinced that something is real before I believe in it, and invoking magical properties is not the way to do it. I need tangible, incontrovertible evidence to show that a god exists before I'll believe in it. Just showing me words in an old book is not going to do it.
Christian apologetics is the art of rolling a dog turd in sugar and selling it as a donut.