How exactly does belief in God make a substantive meaning to life? Life here on earth is meaningless, just a test to hope you get into heaven. Play by God's rules or go to hell. Then once there you spend eternity doing more of God's bidding and getting some sort of pleasure. You're in heaven for eternity...to what end? What's the point? We live on earth as a test to ensure we have eternal pleasure?
The purpose of life, in the theistic point of view, is to look forward to promised pleasure in the afterlife.
The purpose of life to the hedonistic atheist is to get pleasure in the present life.
What's the major difference?
The only real losers here are folks like me who live by the strictures of Orthodox life but expect no heavenly rewards.