Why do we need a Redeemer who is truly human? One reason is so that he can identify with us. The Bible says he was “in every re- spect . . . tempted as we are, yet without sin” (Heb. 4:15). He went through our experience, so he understands what we go through. He is our High Priest. He understands how we suffer. We understand that God can identify with us, but even as he identified with us—by having lived a hard life, by having been humiliated, and by having gone through humble circumstances—he did it with perfect obedience, not doubting the love of his Father and not wavering from his Father’s path.
That means that not only could Jesus identify with what we experience as humans; he could become the perfect substitute for us. In my sin, I’m separated from God. He’s holy; I am not. For God to be just and holy, he cannot identify with my sin. God had to provide a way for my sin to be put on another. He did that by having his Son come in human likeness, human form, but living perfectly so that he could be the substitute for my sin.
Because Jesus lived a perfect life, when he willingly suffered the penalty for my sin on the cross, it was a right, adequate, and perfect substitute for my sin and for your sin. Jesus could identify with what we go through, but because he lived perfectly in obedience, he became the perfect substitute for our sin. And because he took our sin upon himself, having identified with us, when he rose from the grave and ascended to his Father, he became the perfect advocate for us. He knows our strengths and our weaknesses. Because he retains his humanlike features and functions in his divine nature, he still understands the entirety of our human experience and knows exactly what we need.
But he’s also God. And because Jesus is God, he can accomplish the purposes for which he came. Even now, he can rule our world in such a way that all God intends for our lives will happen. And when he was put to death because he was God, he could not only fully pay the sacrifice for our sin and pay the debt that we owed, he could rise from the grave. Death could not defeat him. Because Jesus is alive, because he is sovereign, because he is divine and risen to God, he continues to advocate for us. But even more than advocate, Jesus accomplishes God’s purposes in our lives. He is the God who accomplishes all that we need, even as he is the man who understands all that we need and provides all that we need.
Jesus, perfect God, perfect man, is the Redeemer that we needed, and he accomplished all that was necessary by identifying with our humanity and doing what God had to do to save us.
AUGUSTINE OF HIPPO
He who existed as the Son of God before all ages, without a beginning, deigned to become the Son of Man in these recent years. He did this although He who submitted to such great evils for our sake had done no evil and although we, who were the recipients of so much good at His hands, had done nothing to merit these benefits. Begotten by the Father, He was not made by the Father; He was made Man in the Mother whom He Himself had made, so that He might exist here for a while, sprung from her who could never and nowhere have existed except through His power.