Let's think, do anyone need to defend their own experiences to know if they're true? You can choose to believe or not, but, unless you're sure that person's lying or mentally ill, you can't do much. But many atheists take the position of "you don't know yourself like I do," which is one of the most insulting attitudes anyone can take. And that comes from people who are not psychologists, not even psychiatrists, and are trying to introduce to the media that religious people, specially Christians, are a threat to the development of society. But Jesus already warned us almost 2 thousand years ago:
Blessed are they which are persecuted for righteousness' sake: for theirs is the kingdom of heaven. Blessed are ye, when men shall revile you, and persecute you, and shall say all manner of evil against you falsely, for my sake. Rejoice, and be exceeding glad: for great is your reward in heaven: for so persecuted they the prophets which were before you.
And the new brand of persecution is not with the sword, the weapons or massive destruction ammunition. Is with words, with propaganda, putting key people in positions of power to influence. This is my advice for Christians who try to present God (or Christian beliefs) to atheists: TRY NOT TO. Why? Are you being mean to atheists? Do you want atheists to get lost? Obviously not, but atheists won't believe anything you say regarding God. The mind of someone who is a sincere atheist (not just a kid who wants to be rebel for the sake of it) is one who will always want "evidence" or "proof." Just as the legal motto "innocent until proven guilty," atheists will think "no God until proven wrong." The only way a real atheist will believe in God is when he (or she) has a personal encounter with the Almighty Itself, and that's something you and me can't do, even if we can present solid and contundent arguments. Remember how did we get saved and believe in God. For some people it's easier than others.