St. John Chrysostom: "...do you see that He everywhere declares that He has been sent..."

"I have come in My Father's name, and you receive Me not; if another shall come in his own name, him will you receive". (John 5:43)

2. Do you see that He everywhere declares that He has been sent, that judgment has been committed to Him by the Father, that He can do nothing of Himself, in order that He may cut off all excuse for their unfairness? But who is it that He here says shall come in his own name? He alludes here toAntichrist, and puts an incontrovertible proof of their unfairness. For if as loving God ye persecute Me, much more ought this to have taken place in the case of Antichrist. For he will neither say that he is sent by the Father, nor that he comes according to his will, but in everything contrariwise, seizing like a tyrant what belongs not to him, and asserting that he is the very God over all, as Paul says, 'Exalting himself above all that is called God, or that is worshipped, showing himself that he is God.' This is to 'come in his own name.' I do not so, but have come in the Name of My Father. 

That they received not One who said that He was sent of God, was a sufficient proof that they loved not God; but now from the contrary of this fact, from their being about to receive Antichrist, He shows their shamelessness. For when they received not One who asserts that He was sent by God, and are about to worship one who knows Him not, and who says that he is God over all, it is clear that their persecution proceeded from malice and from hating God. On this account He puts two reasons for His words; and first the kinder one, That ye may be saved; and, That ye may have life: and when they would have mocked at Him, He puts the other which was more striking, showing that even although His hearers should not believe, yet that God was wont always to do His own works. 

Now Paul speaking concerning Antichrist said prophetically, that God shall send them strong delusion — that they all might be judged who believed not the truth, but had pleasure in unrighteousness. Christ said not, He shall come; but, if He come, from tenderness for His hearers; and because all their obstinacy was not yet complete. He was silent as to the reason of His coming; but Paul, for those who can understand, has particularly alluded to it. For it is he who takes away all excuse from them.