If they are truly friends, you must like them for reasons that have nothing to do with their beliefs and religious practices. Before arguing with them, you might well ask yourself if it's worth it. Losing a good friend for no reason other than their taste in imaginary friends seems a bit silly to me, and I would hesitate to make it an issue unless they were shoving their beliefs on you. And if they are becoming pains in the ass -- proselytizing and so forth -- then perhaps they aren't such good friends to begin with. My attitude IRL is that if people keep their beliefs to themselves, there is no good reason to engage them. If they insist on trying to convert me, or if they actively try to insert their beliefs into the public realm at the expense of the 1st Amendment, then they're fair game and deserve whatever withering contempt they are given.
If you must argue with them, remember that they (the claimants) bear the burden of evidence. You believe a god exists? Fine. What's your evidence? Then get ready to deal with a freight train of unsubstantiated claims, pseudo-philosophical apologetic bullshit, quotes from their holy book, passive-aggressive veiled threats, logical fallacies galore, and emotional manipulation.
In other words, they have nothing. You just have to be adept at spotting the rhetorical sleight-of-hand. This forum is crammed with examples of what to watch for.
If you must argue with them, remember that they (the claimants) bear the burden of evidence. You believe a god exists? Fine. What's your evidence? Then get ready to deal with a freight train of unsubstantiated claims, pseudo-philosophical apologetic bullshit, quotes from their holy book, passive-aggressive veiled threats, logical fallacies galore, and emotional manipulation.
In other words, they have nothing. You just have to be adept at spotting the rhetorical sleight-of-hand. This forum is crammed with examples of what to watch for.