It occurred to me that folks that assert the existence of God - specifically the Christian God - without providing evidence or sound rational justification, may be playing to a pretty uncritical audience.
If the consumer of this proclamation is uncritical or ambivalent, then the assertion that "God is real" may simply satisfy the general feeling that there is something greater than we are at work in the universe. This general story, that there's a personal agent spinning the dials of existence, has been passed down for millennia to this very day. Depending on when and where you were born, the story is slightly different.
These stories are obsolete. They ignore the observable and magnificent reality that we live in - that each of us is unique, that all of us together are alone (so far as we can tell) in an enormous universe, that we humans have a duty to cherish each other and preserve each other for as long as we can so that we can explore this life, this universe, and someday travel to the stars and insure the survival of our descendants until the stars no longer shine.