How do we know that Christ's humanity is essential for salvation?

Christ's humanity is essential for salvation because it enables Him to be our representative before God. According to scripture, it was necessary for the Lord Jesus to be made like His brethren, having taken part in flesh and blood (Hebrews 2:14). This identification with humanity ensures that He is able to fulfill the law's demands and bear its penalty on our behalf. Without His humanity, He would lack the capacity to truly mediate for mankind.

Moreover, the perfect union of Christ's divine and human natures means that His actions and sufferings are not only representative but are also infinitely effective. His obedience to the law as a human, paired with His divine nature, imparts a special significance to His work. Therefore, the doctrine of Christ's humanity is not merely an abstract theological point but a vital truth that informs our understanding of how His work accomplishes our salvation, making it applicable to our lives.