Either Christianity is true or it's false. If you bet that it's true, and you believe in God and submit to Him, then if it IS true, you've gained God, heaven, and everything else. If it's false, you've lost nothing, but you've had a good life marked by peace and the illusion that ultimately, everything makes sense. If you bet that Christianity is not true, and it's false, you've lost nothing. But if you bet that it's false, and it turns out to be true, you've lost everything and you get to spend eternity in hell.