Islam is pretty tricky and if you don't have a decent background in the Gospel they will deceive you. One muslim man always asks to show one place where Jesus claimed to be God. He says he will convert to Christianity if you can. Of course, he knows it is not possible because Jesus openly said he would not use self-witness. So Jesus didn't perform in such a way. Jesus allowed others to bear witness. As in John 5 Jesus allowed a healed blind man to testify before the leaders.
John 5:15
The man departed, and told the Jews that it was Jesus, which had made him whole.
Jesus did his works and let them testify. Jesus used little self-witness, he did not see it as appropriate.
John 5:31
If I bear witness of myself, my witness is not true.
Jesus did acknowledge that God was his Father. He could not deny such. Yet he didn't make self-witness his way of operation.
John 5:18
Therefore the Jews sought the more to kill him, because he not only had broken the sabbath, but said also that God was his Father, making himself equal with God.
So, Jesus refused to self-witness as his authority. Righteous men do not boast of themselves. Muslim's know this and know there are few statements of Christ bragging on his nature. Self-witness could have brought an accusation of sin. Jesus rejected self-witness but said there are true witnesses. Jesus used good witnesses such as prophets and teachers. All the prophets testified of him. Consider Isaiah 8 where God used true witnesses as prophets.
Isaiah 8:2
I will get reliable witnesses, Uriah the priest and Zechariah the son of Jeberachiah to attest for me.
The first witness used by Christ was John the Baptist. Satan is smart in asking for self-witness statements because he knew Jesus wouldn't stoop to such, then he could use his simple argument to disturb the simple. Jesus simply let others, including his Father, bear witness.
John 5:32
There is another that beareth witness of me; and I know that the witness which he witnesseth of me is true.
John 5:33
Ye sent unto John, and he bare witness unto the truth.
When they asked John about Jesus John confirmed Jesus was the messiah and he witnessed the Spirit descend upon Jesus. John 1:20-35 bears record from John to the Pharisees that
That the one was already among them, so he couldn't be a later prophet like Muhammed. v
The next day John points out Jesus before them
John testifies that Jesus was before him, Jesus pre-existed John even though John was born months before.
John testifies he saw the Spirit descend upon Jesus
John confirms a message from God the Father that Jesus is the one baptizing with the Holy Spirit
John confirms Jesus is the Son of God.
John confirms Jesus is the one referred to as "Lord", one who gathers a body under his authority.
John confirmed JChrist's purpose was to take away sins.
Thus, John had previously born witness before the Pharisees, but they basically and silently rejected John's witness. Yet, Jesus said that John wasn't the strongest witness. Jesus would not rely on any man. John's testimony was able to convince men to salvation, but wasn't the definitive witness.
John 5:41
I receive not honour from men.
The true and best witness was the Father himself. It was the only witness that was necessary in the eyes of Christ.
Muslims miss this point, the Father himself confirmed Jesus was the Son of God, and God in nature. Muslims reject the Fathers witness that was revealed in works and scripture. Jesus declared those rejecting the Father's witness do not have a true love of God.
John 5:36
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.
John 5:37
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.
Jesus declares the Father bore witness to Jesus in works and in Scripture. Scripture is inspired of God and scripture declares
Heb.1:5-8
unto the Son he says, thy throne O God is forever and ever
So, Islam rejects the witness of the Father.
Psalms 2:7
I will tell of the decree: The Lord said to me, "you are my Son, this day have I begotten thee"
Jesus knew those fighting against this truth did not truly know or love God, not the Pharisees who rejected John and the Fathers witness, nor later teachers who rejected his true purpose and identity. They claim to submit but had no true love,