Since God dwells within everyone*, everyone has a relationship with God, regardless of whether they’re aware of it or not, whether they believe or disbelieve.
That’s my 2¢ opinion, anyway.
*Everyone born with a conscience, anyway.
I don’t like the idea that conscience is related to God. I’m very secular in morality. The idea that we need God at all to be empathetic people is, in my opinion, unfair.
FWIW, this is something I think the Dalai Lama tried to address in Beyond Religion. I don’t think he actually succeeded in what he set out to do, but it was a worthwhile effort, and I’d recommend the read.