Jesus said to them, “I am the bread of life; he who comes to Me will not hunger, and he who believes in Me will never thirst. But I said to you that you have seen Me, and yet do not believe. All that the Father gives Me will come to Me, and the one who comes to Me I will certainly not cast out. John 6:35–37, NASB
Human reason, which is worldly wisdom, is useless for anyone to rely on in order to be saved. Our salvation is a work by all three persons in the Holy Trinity. God the Father chose his people before the foundation of the world. He set into motion all of the circumstances that would result in all of them becoming part of the Family of God. The Son, Jesus Christ, became the God-Man. He became flesh and dwelt among us. He lived a perfect, sinless life then was murdered by wicked men, dying a horrible death by crucifixion.
While dying on the cross, the Father poured out His wrath upon the Son. This wrath was against the sin of those whom He elected. Jesus became sin on their behalf. He knew no sin, but He became separate from the Father because of their sin. His death paid the price for their sin. Jesus was three days and nights in His tomb, but rose from the dead. His resurrection paved the way for all who believe on Him as Lord and Saviour for their future resurrection.