A friend asked “what is the most essential belief in Christianity.” This is what I said:
I’d say the one essential belief (since you asked it that way) is we are created and called for loving God with our whole heart and loving our neighbor as ourselves (Jesus said this was the most essential thing, and added “do this and you will live” which is profound). But on the next tier, to make that possible in grace, I’d say there are FIVE “sacred mysteries” that are core and essential (the Trinity, humanity and divinity of Christ, incarnation, crucifixion and resurrection).
