Dogmatic Decree of the 6th Ecumenical Council:
Following the five holy Ecumenical Councils and the holy and approved Fathers, with one voice defining thatour Lord Jesus Christ must be confessed to be very God and very man, one of the holy and consubstantial and life-giving Trinity, perfect in Deity and perfect in humanity, very God and very man, of a reasonable soul and human body subsisting; consubstantial with the Father as touching his Godhead and consubstantial with us as touching his manhood; in all things like unto us, sin only excepted; begotten of his Father before all ages according to his Godhead, but in these last days for us men and for our salvation made man of the Holy Ghost and of the Virgin Mary, strictly and properly the Mother of God according to the flesh; one and the same Christ our Lord the only-begotten Son of two natures un-confusedly, unchangeably, inseparably indivisibly to be recognized, the peculiarities of neither nature being lost by the union but rather the proprieties of each nature being preserved, concurring in one Person and in one subsistence, not parted or divided into two persons but one and the same only-begotten Son of God, the Word, our Lord Jesus Christ, according as the Prophets of old have taught us and as our Lord Jesus Christ himself hath instructed us, and the Creed of the holy Fathers hath delivered to us;
Defining all this we likewise declare according to the teaching of the holy Fathers that Christ has two volitions or wills, and two natural energies, without division or change, without partition or commingling. And the two natural wills are not opposed (by no means!) as the godless heretics have said; but the human will is compliant, and not opposing or contrary; as a matter of fact it is even obedient to his divine and omnipotent will. For it was necessary for the human will to move itself, but in obedience to the divine will, as the great wisdom of Athanasius has taught. Because just as His human nature is said to be and is the human nature of God the Word, so too the natural will of his human nature is said to be and is God the Word's very own, as He Himself says: "I have come down from heaven not to do my own will, by the will of the Father who sent me" (see John 6.38). Here he calls the will of His human nature His own will, since the human nature also was His own. For his most holy and innocent body, animated by his soul, was not taken away by being deified [or divinized], but stayed true to its own determinate nature. In the same way his human will was not taken away either by being deified, but is preserved rather, according to the word of Gregory the Theologian: "For his will ('his' being understood as referring to the Savior [according to human nature]) is not at all opposed to God; it is wholly deified.
Moreover, in our same Lord Jesus Christ, our true God, we glory in proclaiming two natural energies without division or change, without partition or commingling, namely, a divine energy and a human energy, as Leo, the teacher in matters relating to God, asserted with utmost clarity: "For each nature performs the functions proper to itself, yet in conjunction with the other nature: the Word does what is proper to the Word, and the humanity what is proper to the humanity" (Tome of Leo). For we absolutely refuse to admit that there is but one natural energy, that of God and of creature; for thus we would either exalt what is created into the divine nature or else degrade what is uniquely proper to the divine nature to the level of creatures; because we know that both miracles and sufferings belong to one and the same person, according to the different natures of which he consists and in which he has his being, as the marvelous Cyril has said. In every way possible, therefore, we uphold our denial both of commingling and of divisions and in this concise utterance we may express the entire matter: We believe that one of the Holy Trinity who, after the Incarnation, is our Lord Jesus Christ, is our true God; and we assert that both his natures clearly appear in his one hypostasis. In it throughout the whole ordered conduct of His life He gave evidence of both his miracles and his sufferings, not just in appearance, but in actuality. The difference of natures within the same one person is recognized by the fact that each nature, in conjunction with the other nature, wills and carries out what is proper to itself. Accordingly, we hold that there are two natural wills and energies concurring in harmony for the salvation of the human race. (6th Ecumenical Council of Constantinople, 680-681: Dogmatic Decree)