There are many scriptural proofs that not only prove the Jesus was indeed the Son of God, but that He also was God that Muslims deny.
Jesus Said:
(Matthew 16:13-19) When Jesus came into the coasts of Caesarea Philippi, he asked his disciples, saying, Whom do men say that I the Son of man am? 14 And they said, Some say that thou art John the Baptist: some, Elias; and others, Jeremias, or one of the prophets. 15 He saith unto them, But whom say ye that I am? 16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God. 17 And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. 18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. 19 And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
(John 14:6-9) Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me. 7 If ye had known me, ye should have known my Father also: and from henceforth ye know him, and have seen him. 8 Philip saith unto him, Lord, shew us the Father, and it sufficeth us. 9 Jesus saith unto him, Have I been so long time with you, and yet hast thou not known me, Philip? he that hath seen me hath seen the Father; and how sayest thou then, Shew us the Father?
(John 8:56-59) Your father Abraham rejoiced to see my day: and he saw it, and was glad. 57 Then said the Jews unto him, Thou art not yet fifty years old, and hast thou seen Abraham? 58 Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am. 59 Then took they up stones to cast at him: but Jesus hid himself, and went out of the temple, going through the midst of them, and so passed by.
This verse says it all because in Exodus 3:14 it was God that called Himself the "I AM"
And God said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you.
God Said:
(John 3:17) And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.
The Archangel Gabriel Said:
(Luke 1:26-35) And in the sixth month the angel Gabriel was sent from God unto a city of Galilee, named Nazareth, 27 To a virgin espoused to a man whose name was Joseph, of the house of David; and the virgin’s name was Mary. 28 And the angel came in unto her, and said, Hail, thou that art highly favoured, the Lord is with thee: blessed art thou among women. 29 And when she saw him, she was troubled at his saying, and cast in her mind what manner of salutation this should be. 30 And the angel said unto her, Fear not, Mary: for thou hast found favour with God. 31 And, behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS. 32 He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: 33 And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end. 34 Then said Mary unto the angel, How shall this be, seeing I know not a man? 35 And the angel answered and said unto her, The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God.
John the Baptist Said:
(John 1:32-34) And John bare record, saying, I saw the Spirit descending from heaven like a dove, and it abode upon him. 33 And I knew him not: but he that sent me to baptize with water, the same said unto me, Upon whom thou shalt see the Spirit descending, and remaining on him, the same is he which baptizeth with the Holy Ghost. 34 And I saw, and bare record that this is the Son of God.
The Apostles Said:
(John 20:26-28) And after eight days again his disciples were within, and Thomas with them: then came Jesus, the doors being shut, and stood in the midst, and said, Peace be unto you. 27 Then saith he to Thomas, Reach hither thy finger, and behold my hands; and reach hither thy hand, and thrust it into my side: and be not faithless, but believing. 28 And Thomas answered and said unto him, My Lord and my God.
So, not only did He recognize His as just the Son of God, but as God. Notice Jesus did not correct him.
(John 20:31) But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
They that Crucified Him Said:
(Matthew 27:35-43) And they crucified him, and parted his garments, casting lots: that it might be fulfilled which was spoken by the prophet, They parted my garments among them, and upon my vesture did they cast lots. 36 And sitting down they watched him there; 37 And set up over his head his accusation written, THIS IS JESUS THE KING OF THE JEWS. 38 Then were there two thieves crucified with him, one on the right hand, and another on the left. 39 And they that passed by reviled him, wagging their heads, 40 And saying, Thou that destroyest the temple, and buildest it in three days, save thyself. If thou be the Son of God, come down from the cross. 41 Likewise also the chief priests mocking him, with the scribes and elders, said, 42 He saved others; himself he cannot save. If he be the King of Israel, let him now come down from the cross, and we will believe him. 43 He trusted in God; let him deliver him now, if he will have him: for he said, I am the Son of God.
(Matthew 27:54) Now when the centurion, and they that were with him, watching Jesus, saw the earthquake, and those things that were done, they feared greatly, saying, Truly this was the Son of God.
Anytime a Muslim tries to tell you that Jesus never said "I am the Son of God", ask them why they don't apply the same test to the Quran about Mohammed. Mohammed never says in the Quran the words "I am a prophet".
Without Jesus, there is no provision of salvation. Allah offers no such promise. Muslims believe Allah will be merciful to them based on his evaluation of their performance. But salvation is never sure, and is never a promise.