Why is it important to believe in the true humanity of Christ?

The true humanity of Christ is essential for the doctrine of salvation because it ensures that He could genuinely represent humanity before God. As stated in Hebrews 2:17, Jesus had to become like His brethren in every respect so that He could act as a merciful and faithful high priest. This incarnate nature allows Him to understand our struggles and temptations, yet remain without sin. His full humanity was necessary for Him to suffer and die as our substitute, fulfilling the requirements of the law for our redemption. Thus, affirming His humanity is crucial for supporting the entirety of God's redemptive plan.