I know the answer is obviously no, but I need a good explanation for a friend. My friend and I are having a discussion on the sinlessness of Jesus. He acknowledges that Jesus did not commit sin, but he also says Jesus COULD have sinned if he chose to. I posit that Jesus could not sin because Jesus is God and God cannot sin.
There is also debate on the exact meaning of “tempted”, because the Bible says Jesus was tempted. I claim he was tempted in the sense that the devil tried to lure him into something, but that Jesus was not internally tempted to act on that. My friend however claims that the fact that Jesus COULD be tempted internally but chose not to act if one of the things that makes him such a good example for us.
The main I’m wondering is (from his question):
If God is omnipotent, why can he not sin?
God is ALL Good; He cannot do evil.
Regarding Our Lord: A truly free will is a will aimed toward the good; a failure in exercising free will towards the good leads to slavery to sin. Thus, God Who is All God cannot fail in His will always desiring His own Goodness. This is why Original Sin and actual sin impact our ability to choose the Good; but, as we grow in our identity in Christ, our will becomes freer and is less apt to choose the non-good.
Further, Christ as a healer must have what He is going to share, i.e., must be fully, i.e., perfectly human and Divine or He could not heal us. He gives us the health, as it were, He has. If He did not have this health we, being sick, could not receive healing. So it is not Christ Who is not fully human, it is we in our fallen state who are not yet fully human. Only when we by His merits are conformed to Him by divine grace will our humanity be all that it should be. Christ is the Model and Goal for humanity, not vice-versa.
Christ has the fully human nature, i.e., one not wounded by sin. His humanity is therefore graced and in harmony with the Divine. For us to be tending toward sin is for us NOT to be fully human; therefore we are not the vantage point of healing of our wounded nature but He is. If follows that for Him to heal our infirmity He must bring health to our infirmity. We can’t give what we don’t have, so He must have this health of being fully human, i.e., in harmony with God in order to give it to us by grace. He therefore could not sin, which makes him perfectly human, not less human.
Temptation for Him is not exactly the same as for us. The world and the devil would tempt Him from outside, but there was no concupiscence in Him that could pull Him towards sin within His humanity. Satan was presenting Him with all the earthly possibilities open to Him; this was a temptation from outside of Himself. IOW, it was an urging from outside, not a desire rising from concupiscience (and He wasn’t subject to concupiscience, i.e., the internal temptations arising from a fallen nature). What He experienced in the Passion is the natural repulsion of the flesh which ought not to die, is not supposed to die, to undergo that separation of body and soul.
Since He was fully human, He would have felt this separation and its preliminaries more than we do. Moreover, He would have felt the abandonment of His Father more than we do (since He was closer to Him than we ever were or could be). It is because He could not sin that when he undergoes this separation of death He experiences “temptation” in a way as we do. But in another way He doesn’t; He was not bent towards sin. He would not have experienced inordinate lust or greed, or gluttony, etc… His trials came from outside though they are experienced inside, e.g., suffering and death. While He has consciousness of being the Son, in His sacred humanity He is able to suffer from forces outside Himself (hunger, thirst, obdurancy of others, etc.); and as Man He acquired sensible knowledge, had human emotions and thus could feel sorrow and fear; so He brings what He encounters in His Body to His Father because He is in relation to Him and is the Perfect Man at prayer, submitting His human will to the Will of the Father.
Consider the doctrine of the Theotokos: Mary is the Mother of God because the Person born of her is Divine. IOW, she didn’t just give birth to Christ’s human nature, but gave birth to a Person. The Son, the Second Person of the Divinity, took upon Himself a human nature; joined to that human nature He is known as Jesus, but there is only one Person (God the Son) who is undivided in Himself while being both God and Man - and it is a person who sins or not, not a nature. The Person of God the Son cannot sin.