Something that seems to be missing from this whole conversation is one of the main understandings of Christianity, which could be summed up in Jesus' statement when the religious authorities were appalled at the fact that Jesus would eat with "sinners"(Matthew 9:12-13). Jesus said, "Those who are well have no need of a physician, but those who are sick.  Go and learn what this means, 'I desire mercy, not sacrifice.' For I have come to call not the righteous but sinners."  The billboard's suggestion that millions of us can be just fine without God isn't in any way helpful to the millions of people who can't figure out how on earth to escape who they are and what they do as a result.  Jesus came to give "abundant life" to everyone who otherwise are caught in the quagmire of impossible life/personality circumstances.  Faith in Jesus creates a new beginning, bringing hope to a previously hopeless life.  And by the way, identifying myself as "good" is a real stretch, which any amount of real introspection will reveal.  Looking around at the mess our world is in shows how good we are at being good.  Even Jesus said that not he, but only God, is "good."