Well my muslim friend and I are having a debate about our faiths and the main issue that he (and most muslim's) have is with Jesus. The questions asked were how can Jesus be man and God? Is Jesus the Son of God or God?, and how can God have a son? Also that Jesus doesn't claimed to be God but that the bible was changed from Greek and misinterpreted.
Jesus does claim to be God.
54 Jesus answered, If I honour myself, my honour is nothing: it is my Father that honoureth me; of whom ye say, that he is your God:
55 Yet ye have not known him; but I know him: and if I should say, I know him not, I shall be a liar like unto you: but I know him, and keep his saying.
56 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.
(Joh 8:54-1 KJV)
When Jesus said "I am" He was claiming to be the one who spoke with Moses. Remember the Lord said to Moses, tell them I am has sent you. That is why the Jews pick up stones to stone Him.
He is the Son of God.
Jesus Himself said, I have come out of the Father. David also prophesied in Psalm 2 concerning the Christ.
KJV
Psalm 2:1 Why do the heathen rage, and the people imagine a vain thing?
2 The kings of the earth set themselves, and the rulers take counsel together, against the LORD, and against his anointed,
saying,
3 Let us break their bands asunder, and cast away their cords from us.
4 He that sitteth in the heavens shall laugh: the Lord shall have them in derision.
5 Then shall he speak unto them in his wrath, and vex them in his sore displeasure.
6 Yet have I set my king upon my holy hill of Zion.
7 I will declare the decree: the LORD hath said unto me,
Thou art my Son; this day have I begotten thee.
8 Ask of me, and I shall give
thee the heathen
for thine inheritance, and the uttermost parts of the earth
for thy possession.
9 Thou shalt break them with a rod of iron; thou shalt dash them in pieces like a potter's vessel.
10 Be wise now therefore, O ye kings: be instructed, ye judges of the earth.
11 Serve the LORD with fear, and rejoice with trembling.
12 Kiss the Son, lest he be angry, and ye perish
from the way, when his wrath is kindled but a little. Blessed
are all they that put their trust in him. (Psa 2:1-12 KJV)
Solomon also speaks of God's Son.
Exodus 3:13 (KJV)
13 And Moses said unto God, Behold,
when I come unto the children of Israel, and shall say unto them, The God of your fathers hath sent me unto you; and they shall say to me, What
is his name? what shall I say unto them?
Proverbs 30:4 (KJV)
4 Who hath ascended up into heaven, or descended? who hath gathered the wind in his fists? who hath bound the waters in a garment? who hath established all the ends of the earth? what
is his name, and what
is his son's name, if thou canst tell?
As far as Jesus being God, many get confused because the word God is used in two different ways. The word that is translated God is "Theos," it means deity or divinity. Jesus is deity, He is divine. He
IS NOT the Father. The word God is used as a name for the Father, He is divine. The Father is God, the deity, Jesus is His Son, He is also deity.
I hope that helps explain some things to your friend.