If G-d sent me an email, or even a phone call, I think that would do it for me.
If an email; it would probably end up in your junk folder.
And a phone call, with no caller ID, would be met with a "HEY!! Who is this???
you are in a flood, a rowboat happens by and you say no thanks, I've prayed and God will take care of me, a fireboat comes toward you, you wave it away saying I'm depending on God, a helicopter passes overhead and you wave it off knowing that God will save you....you drown.....at the pearly gates you complain to God that He didn't come to save you....He says, I sent a rowboat, a fireboat and a helicopter to get you but you refused My gift.......we are all free to refuse His gifts!!!