John 5:36-38
The witness of the Father: V. 36. But I have greater witness than that of John; for the works which the Father hath given Me to finish, the same works that I do bear witness of Me that the Father hath sent Me. V. 37. And the Father Himself which hath sent Me hath borne witness of Me. Ye have neither heard His voice at any time nor seen His shape. V. 38. And ye have not His Word abiding in you; for whom He hath sent, Him ye believe not.
The testimony of John was valuable for their sakes only; Jesus did not need the witness of men. He could appeal to testimony greater than John's. For all the works which He was performing had been given Him by the Father to carry out in just that way; all the miracles of Jesus served a definite purpose. Through them God Himself bore witness to Him that He was the Son of God. If He had been a deceiver and cheat, God would not have given Him the power to perform such wonderful deeds. No one that saw His miracles and judged them with an unbiased, open mind, could deny His divine mission. All His works were evidence of greater weight than John's. The entire appearance of Jesus and the manifestation of His glory called out loudly in testimony of His divine mission.
And in addition to this testimony, undeniable, unassailable, there was the witness of the Father's voice, through the writings of the prophets. God did not appear to the Jews in a visible manifestation; they did not hear His voice, they did not see His form. And yet, there was the evidence contained in the Word of the Old Testament, so clear and unmistakable that there could be no doubt as to its correctness.
In spite of all that, however, His Word had found no abiding place in their hearts; they did not accept the testimony of God Himself. For the reception accorded to the delegate of God, to the Son of God Himself, is a proof of the fact that the Word of God does not abide in them. If they actually believed God in the witnesses of the Old Testament, as they professed to, they would receive His great Minister, the Prophet to whom Moses pointed.
It is the essence of unbelief that people refuse the Word of God an abiding place in their heart, that they simulate religion in their lives, but have no true religion in their hearts.