Some people have seen a hint of the trinity in this verse. They seem to read it this way, “He that hath seen me hath seen the Father; because I am the Father.” Yet, this is an impossible interpretation of this verse. Jesus said, “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” (John 5:37). Jesus had said that his hearers had never literally seen the Father, so when He told His disciples that they have “seen the Father” He was not speaking in a literal sense. Instead, they had seen the Father’s character manifested in His life. Jesus clarified his meaning in the very next verse: “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” (John 14:10). Here Jesus explained that when people saw the works of Jesus and heard His words, they were seeing the Father because the Father was the one doing the works in Jesus.
This is similar to what Paul said when he wrote, “I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me” (Galatians 2:20). Here Paul claimed that the life people saw in him was not his life, but the life of the Son of God. He was saying, “If there is anything good in me, it is not me doing it, but Jesus who lives in me.” Paul also wrote, “that the life also of Jesus might be made manifest in our mortal flesh” (2 Corinthians 4:11).
If Christ’s life is fully manifested in my life, it would be appropriate for me to say, “If you have seen me you have seen Christ, because Christ is living in me.” This is essentially the same thing Jesus was saying about His Father. He manifested the life of the Father more fully than anyone had done, and since He knew it was His Father doing the works and giving Him the words to say, He was giving credit to whom credit was due. He was not in any way trying to convince His disciples that He is part of a “three in one” God.