John 8:14 and John 5:31
- Not true (John 5:31-32) - "If I alone bear witness of Myself, My testimony is not true. 32"There is another who bears witness of Me, and I know that the testimony which He bears of Me is true."
- Is true (John 8:14) - "Jesus answered and said to them, "Even if I bear witness of Myself, My witness is true; for I know where I came from, and where I am going; but you do not know where I come from, or where I am going."
In John 5:31, the context is Jesus speaking about how He depends upon the Father and how He is seeking the will of the Father. John 5:30-32 says, "I can do nothing on My own initiative. As I hear, I judge; and My judgment is just, because I do not seek My own will, but the will of Him who sent Me. 31If I alone bear witness of Myself, My testimony is not true. 32There is another who bears witness of Me, and I know that the testimony which He bears of Me is true."
The word "alone" is not in the Greek but is included in the NASB translation, though not the NIV or KJV. Contextually, Jesus is not speaking as one alone, but as one dependent on the Father and that His judgments are true because He does the will of the Father. Jesus is reflecting on the Old Testament law that didn't allow the testimony of one person to condemn another to death. Two witnesses were needed to establish the fact:
"One witness shall not rise up against a man for any iniquity, or for any sin, in any sin that he sinneth: at the mouth of two witnesses, or at the mouth of three witnesses, shall the matter be established," (Deut. 19:15). Matthew 18:16 says, ". . . in the mouth of two or three witnesses every word may be established." See also 2 Cor. 13:1; Heb. 10:28.
In John 8:14, Jesus says, "IF" (kan in the Greek) I bear witness of Myself, My witness is true. But He was speaking of being the light of the world, v. 12, and the Pharisees accused Him of bearing witness of Himself. Jesus was simply telling the truth that if He did, it would be true.