1)Jesus(pbuh) told 3 times in New-testament that God is One
(Mk 12:29)"Hear, O Israel, the Lord our God, the Lord is one"
(Eph 4:6) "There is one body and one Spiritjust as you were called to one hope when you were called 5one Lord, one faith, one baptism; 6one God and Father of all, who is over all and through all and in all."
(Jas 2:19)"You believe that there is one God. Good! Even the demons believe thatand shudder"
Paul said god is three---He developed the concept of TRINITY Which is nowhere to be found in BIBLE----Trinity was doctrine derived 300 years after jesus(pbuh) death ---if it was a true doctrine Jesus(pbuh) would explicitly spoken of it but its not the case----The only verse close to TRINITY was in Gospel OF Jhon' In 'King James Version' of Bible But this verse is deleted in the 'New Revised Standard Version' of Bible as the scholars of Bible thought it was fabricated into Bible----Apart from that there is not a single verse in complete Bible which even remotely speaks about TRINITY
This is what is written in the opening page of New Revised Standard Version
"King James Version has serious defects. By the middle of the nineteenth century, the development of biblical studies and the discovery of many biblical manuscripts more ancient than those on which the King James Version was based made it apparent that these defects were so many as to call for revision."
2)Jesus(pbuh) taught the Law of God
Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil"- Matthew 5:17-29
"Here is the patience of the saints: here are they that keep the commandments of God, and the faith of Jesus." -Revelation 14:12.
"By this we know that we love the children of God, when we love God, and keep his commandments. For this is the love of God, that we keep his commandments: and his commandments are not grievous." -1 John 5:2-3
According to Jesus(pbuh) Law of Moses(pbuh) is still valid and if you read the Old-Testament Moses said there are three prophets to follow :
1)Jhon the baptist
2)jesus
3)Is still a mystery
But Paul broke the law of God----and told the law of previous Prophets isn't needed any more---According to him "Jesus fulfilled the law" which is in direct contradiction of what Jesus(pbuh) said:
Gospel of John chapter 16 verse 12-14:
"I have yet many things to say unto you, but ye cannot bear them now. Howbeit when he, the Spirit of truth is
come, he will guide you unto all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come. He shall glorify me".
And according to Jesus(pbuh) there would be one more prophet to follow him
1)Is still a mystery
Quran replies in Surah Al-Araf chapter 7 verse 157:
"Those who follow the Messenger, the unlettered Prophet, whom they find mentioned in their own (scriptures) in the law and the Gospel"
Conclusion
So we can clearly see Paul and his theologians are going directly against Jesus(pbuh) teachings---This is how Quran Replies to them
"Those people who say that God is the third of three are defying [the truth]: there is only One God. If they persist in what they are saying, a painful punishment will afflict those of them who persist. Why do they not turn to God and ask his forgiveness, when God is most forgiving, most merciful? The Messiah, son of Mary, was only a messenger; other messengers had come and gone before him; his mother was a virtuous woman; both ate food. See how clear We make these signs for them; see how deluded they are." (Qur'an 5:72)
"People of the Book, do not go to excess in your religion, and do not say anything about God except the truth: the Messiah, Jesus, son of Mary, was nothing more than a messenger of God, His word, directed to Mary, a spirit from Him. So believe in God and His messengers and do not speak of a 'Trinity'stop, that is better for youGod is only one God, He is far above having a son, everything in the heavens and earth belongs to Him and He is the best one to trust." (Qur'an 4:171)