No, He was not, or they would not have rejected. Therefore, they never put John 3:16 faith in Him. And, when we look at the entire scripture, we discover that is true:
15 "Watch out for false prophets. They come to you in sheep's clothing, but inwardly they are ferocious wolves. 16 By their fruit you will recognize them. Do people pick grapes from thornbushes, or figs from thistles? 17 Likewise every good tree bears good fruit, but a bad tree bears bad fruit. 18 A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. 19 Every tree that does not bear good fruit is cut down and thrown into the fire. 20 Thus, by their fruit you will recognize them. 21 "Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. 22 Many will say to me on that day, 'Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?' 23 Then I will tell them plainly, 'I never knew you. Away from me, you evildoers!'
Jesus begins the passage in question saying they are false prophets and wolves. It is these people who will, cynical to the last, be saying to the Lord, "...did we not prophesy in YOUR name..."
Users to the end. One reason they needed to be consigned to outer darkness for eternity.
Then how were they able to prophesy, heal the sick, perform deliverance, etc?
. . . or they would not have rejected.
Rejected what? What is it that they rejected?