God bless you and greetings in the name of Jesus Christ who boldly declared that he was who God said he was (John 5:32).
John 8 wasn’t the first time Jesus boldly declared who he was. John records how he repeatedly did so on other occasions.
I can of mine own self do nothing: as I hear, I judge: and my judgment is just; because I seek not mine own will, but the will of the Father which hath sent me. 31 If I bear witness of myself, my witness is not true. 32 There is another that beareth witness of me; [referring to God] and I know that the witness which he witnesseth of me is true.
God declared in His Word what the Messiah would do, and Jesus did those things. Therefore, the words and the works both testified that he was the Messiah.
Ye sent unto John, and he bare witness unto the truth. 34 But I receive not testimony from man: but these things I say, that ye might be saved. 35 He [John] was a burning and a shining light: and ye were willing for a season to rejoice in his light. 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. 37 And the Father himself, which hath sent me, hath borne witness of me [How did God bear witness of him? The same way he bears witness with us by energizing manifestations of the spirit.]. Ye have neither heard his voice at any time, nor seen his shape. [They never operated manifestations.] 38 And ye have not his word abiding in you: for whom he hath sent, him ye believe not. 39 Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me.
It was God’s Word which testified of Jesus Christ. Then when he actually did the work, it established that he was the one to whom God referred in the scriptures. Remember the healing of the man born blind? We need to read this without the punctuation that was added at the end of verse 3.
Jesus answered, Neither hath this man sinned, nor his parents[.] [But] that the works of God should be made manifest in him[,] 4 I must work the works of him that sent me, while it is day: the night cometh, when no man can work.
Jesus specifically stated that the works bore witness of him. The Jews requested of him, “If you be the Christ tell us plainly.”
John 10:25, 37-38:
Jesus answered them, I told you, and ye believed not: the works that I do in my Father’s name, they bear witness of me. . . . [The works that he did should have eliminated any doubt about the words that he spoke.] 37 If I do not the works of my Father, believe me not. 38 But if I do, though ye believe not me [his personal testimony], believe the works: that ye may know, and believe, that the Father is in me, and I in him.
What about us? The same truths apply. We have God in Christ in us. We are what God says we are, and we can do what God says we can do. We speak His Word, and it is confirmed with signs following (Mark 16:20).
Believest thou not that I am in the Father, and the Father in me? The words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works. 11 Believe me that I am in the Father, and the Father in me: or else believe me for the very works’ sake. 12 Verily, verily, I say unto you, He that believeth on me, the works that I do shall he do also; and greater works than these shall he do; because I go unto my Father.
Just like God worked in His only begotten son, Jesus Christ, He will work in the rest of His children the same way.