I do not accept testimony from a human being,… But I have testimony greater than John's. The works that the Father gave me to accomplish, these works that I perform testify on my behalf that the Father has sent me. Moreover, the Father who sent me has testified on my behalf… You search the scriptures, because you think you have eternal life through them; even they testify on my behalf. But you do not want to come to me to have life. "I do not accept human praise; moreover, I know that you do not have the love of God in you. I came in the name of my Father, but you do not accept me; yet if another comes in his own name, you will accept him. How can you believe, when you accept praise from one another and do not seek the praise that comes from the only God? (Jn 5,34-44)
Testimonies and praises are part of life for man. People offer testimonies and long for praises from one another. Often, our piety (prayers, almsgiving, fasting) is for men to see. We perform them in public so that people who see them will bear witness and also praise us for the life of piety. That is why Jesus has said that, when we pray we should do it in private and when we give alms, left hand should not know what the right hand is doing.
Jesus says that he does not accept testimony from human being (v.34) and he does not accept human praises (v.41). Jesus never performs for spectators. Many a times his miracles are done in private and at times people do not know who performed the miracle (Jn 5,13).
He also says that the works given by the Father which he performs are the testimonies and he seeks the praise that comes from the only God. Jesus is immersed in God and God has taken him over totally that whatever he does or says is from God and they are Godly. That is why he could say that “I came in the name of the Father”.
People who perform things for one another and worried about receiving testimonies form one another can not receive persons who come in the name of God: “He came to his own and his own received him not”.