For Protestants, your definition is correct, "faith means believing in the absence of evidence." Absolutely right. That is the definition Martin Luther promoted, which is a large portion of why he was deemed a heretic.
But, you have to understand, not all Christians are Protestants. For non-Protestant Christians, faith requires evidence. Christianity is based on a signal, physical event: resurrection. If this Jesus guy resurrected, then Christianity has an argument, but if he did not, if there …