How do we know that belief in Christ is essential?

The necessity of faith is underscored in John 1:11-12, where it says, 'He came unto His own, and His own received Him not. But as many as received Him, to them gave He power to become the sons of God.' This illustrates that receiving Christ leads to spiritual rebirth and acceptance into God's family. Furthermore, the sermon emphasizes that no sinner born of Adam can believe in Christ without divine intervention, reaffirming the teaching that belief is a gift from God, acting solely by His grace. This doctrine stands opposed to any belief that salvation could be earned or obtained through human effort.