The word 'must' in Mark 8:31 is a divine imperative. Jesus said He MUST suffer, be rejected, killed, and rise again. Why did it have to be this way? So that we would not have to die eternally for our crimes against a holy and righteous God. Pastor Brian Brodersen, in his message titled, "Why It Had To Be So" taken from Mark 8:27-31, shares what we MUST do in response to what Jesus had done: "Believe on the Lord Jesus Christ, and we will be saved!"