Monothelitism is a teaching which began in Armenia and Syria in A.D. 633 and had considerable support during the 7th century A.D. before being officially condemned at the Third Council of Constantinople in favor of dyotheletism. It holds that Jesus Christ has essentially two natures but only one will. This is contrary to the orthodox doctrine of Christology which states that Jesus Christ has two wills (human and divine) which correspond to His divine-human nature.
The monothelite teaching emerged as essentially a compromise position. The miaphysitists could agree that Jesus possessed two natures if He only possessed one will, and some Chalcedonians could agree that Jesus had one will if He had two natures. The monothelite position was promulgated by Sergius I of Constantinople and spread under Pope Honorius I.
The doctrine of the hypostatic union states that the two natures of Christ (His deity and humanity) are united in one Person. This is often referred to as the Chalcedon Creed. The converse, non-orthodox position (i.e., the non-Chalcedon view) is that Jesus’ deity and humanity are united in one nature, the two being united without separation, confusion or alteration. This position is often referred to as miaphysitism.
To conclude, is the teaching of monothelitism biblical? There are numerous texts which could be cited to definitively prove that Christ possessed both a divine and a human will. In Hebrews 10:7, Paul applies to Christ the words of Psalm 40:7-8 – “Then I said, ‘Here I am, I have come – it is written about me in the scroll. I desire to do your will, O my God; your law is within my heart.’” Here, both wills are distinctly marked—the divine (“I desire to do your will, O my God”) and the human will, subject to the divine will (“your law is within my heart”).
Christ Himself draws the same distinction in many places. For example, in John 6:38, Jesus declares, “I have come down from heaven not to do my will but to do the will of him who sent me.” In Matthew, Christ says, “My father, if it is possible, may this cup be taken from me. Yet not as I will, but as you will.” And as Jesus declares in John 10:17-18, “The reason my Father loves me is that I lay down my life – only to take it up again. No one takes it from me, but I lay it down of my own accord. I have authority to lay it down and authority to take it up again. This command I received from my Father.” Clearly, these texts show the divine will which Christ had, in common with the Father and, in contrast, the human will which He subjected to the will of His Father.