God knew man would evolve. People think some of the Old Testament laws are absurd now because we live in a very different culture, a different time period. They had their problems and we have ours. God is constant but man is not, and he foreknew the ever-changing world his people would have to deal with; therefore, and if there is indeed an omniscient God, a Christ-like figure would be our only rational, possible connection to a constant, holy God throughout the evolution of culture and social law. The only answer that makes sense when it comes to relevance regarding religions and time periods is Christ, and the chances are slim that men could have invented it.