I'll keep it short and post a short version of the argument from Wikipedia:
1. If no perfectly loving God exists, then God does not exist.
2. If a perfectly loving God exists, then there is a God who is always open to personal relationship with each human person.
3. If there is a God who is always open to personal relationship with each human person, then there no human person is ever non-resistantly unaware that God exists.
4. If a perfectly loving God exists, then no human person is ever non-resistantly unaware that God exists (from 2 and 3).
5. Some human persons are non-resistantly unaware that God exists.
6. No perfectly loving God exists (from 4 and 5).
7. God does not exist (from 1 and 6).
What do you think of this argument? Good or bad?
I guess you could say that God doesn't have to be perfectly loving if he does exist, but I think the majority of theists believe otherwise. Everything else seems valid to me.