When I was old enough to understand it (which was really old), I realized it was about karma; you reap what you sow as the cliche goes. If you've been bad, bad things happen to you. To put it in a positive sense, if you've been good, good things happen to you. As John Lennon puts it, it is the mathematical equation of the universe.
But it is not so if you're a Christian. Why -- because we didn't bring anything to the table. It's not equal; it's all God. And even if we've been bad, good things will still happen to us. In the same way that bad things also happen to the good people. God's forgiveness transcends our sense of morality. This helps explain the Parable of the Prodigal Son, which is revolting to the good people. Karma seems to come too late to the bad people, if at all.
It's Good Friday today, a day when we commemorate the day when men executed the Christ. I put the Jesus Christ Superstar album on repeat in my Spotify playlist. No Beatles paganism today. Come to think of it, the mystery of Good Friday is we got away with it. Two centuries since the killing of Jesus Christ, God's Son, and humanity has not been abolished and continues to flourish. Karma is a hoax.