Why must Jesus be both God and man?

The dual nature of Christ as both God and man is essential for the doctrine of salvation. As the God-man, Jesus is able to mediate effectively between God and humanity. His divine nature allows Him to represent God fully, while His humanity enables Him to identify with and redeem humankind. Hebrews 1:3 emphasizes that He is the radiance of God’s glory, and His human experience allows Him to be our empathic high priest who understands our weaknesses (Hebrews 4:15). This unique union is necessary for Him to bear the weight of our sins and provide an efficacious atonement.