How do we know Christ must be lifted up?

In John 3:14, Jesus explicitly states that He must be lifted up, referring to His crucifixion, which is essential for the work of salvation. This lifting up is crucial for sinners to receive eternal life. The Old Testament reference in Numbers 21 illustrates this principle; just as Moses lifted up the serpent to bring healing to the Israelites bitten by poisonous snakes, so must Christ be lifted up to heal sinners from the deadly bite of sin and death. This connection demonstrates the provision of God for His people, showing that Christ's sacrifice is the only means by which eternal life is granted. The need for Christ's exaltation is rooted in God's justice and mercy, providing a means for sinners to be justified and granted new life.