If Messiah had been a sinless and perfect man, and no more, He might have yielded a complete obedience to the will of God, but it could have been only for Himself. The most excellent and exalted creature cannot exceed the law of his creation. As a creature, he is bound to serve God with his all, and his obligations will always be equal to his ability. But an obedience acceptable and available for others, for thousands and millions, for all who are willing to plead it, must be connected with a nature which is not thus necessarily bound. A sinner, truly convinced of his obnoxiousness, to the displeasure of God, must sink into despair, notwithstanding the intimation of a Savior, if he were not assured by the Scripture that it was a divine person in the human nature who engaged for us. It is this, alone, which affords a solid ground for hope, to know that He who was before all, by whom all things were made and by whom they consist, assumed the nature of man, that the great lawgiver Himself submitted to be under His own law. This wonderful condescension gave an immense value and dignity to all that He did, to all that He suffered. Thus, He not only satisfied but honored the law. So that we may, without hesitation, affirm that the law of God was more honored by the Messiah, in His obedience to it, during the few years of His residence upon earth, and terminated by His last and highest acts of obedience in submitting to the death of the cross than it could have been by the un-sinning obedience of all mankind to the end of time.
From: Messiah: Fifty Expository Discourses on the Series of Scriptural Passages Which Form the Subject of the Celebrated Oratorio of Handel, Preached in the Years 1784 and 1785 in the Parish Church of St. Mary Woolnoth, Lombard Street by John Newton (New Haven: Nathan Whiting, 1826), pp. 63-64. This extract is from sermon no. 5, on Isaiah 7.14. The volume this extract is from comprises Volume 3 of The Works of the Rev. John Newton.