«The Messiah, son of Mary, was not but a messenger; [other] messengers have passed on before him. And his mother was a supporter of truth. They both used to eat food. Look how We make clear to them the signs; then look how they are deluded Say, “Do you worship besides Allah that which holds for you no [power of] harm or benefit while it is Allah who is the Hearing, the Knowing?” Say, “O People of the Scripture, do not exceed limits in your religion beyond the truth and do not follow the inclinations of a people who had gone astray before and misled many and have strayed from the soundness of the way.”»
In these verses of the Noble Qur’an, Allah Ta’ala tells us that Sayyiduna ‘Isa ‘alayhi as-salam used to eat food – a trait of a human being. A deity does not need food. This is a clear statement that the Islamic view regarding Sayyiduna ‘Isa ‘alayhi as-salam is that he is human.
On the other hand, Catholic, Orthodox, and Protestant Christians confess together that the God of the Bible is Trinitarian. Many questions arise from this ostensibly fundamental Christian belief. However, this belief developed over time and was entangled with differences amongst Christian scholars, declarations of heresies, and major problems. To this day, Christians cannot give a clear cut reasonable, and rational explanation of the Trinity doctrine.
How did the doctrine of Trinity come about? Who was behind it? Why did all the Christians agree upon Trinity only in the fourth century after Sayyiduna ‘Isa ‘alayhi as-salam. There is a significant amount of debate amongst Christian and non-Christian scholars on this particular issue because this is central to Christian theology.
Development of the Trinity Doctrines
Incarnation: Incarnation was a view held by some Christians based on the Gospel of John. It implies “coming in the flesh.” This means that Christ was the Word, with God and everything came into being through him, i.e., a divine being and he later became a human being, i.e., ‘in the flesh dwelling amongst us’. Amazingly, the Gospel of John does not speak of the virgin birth. It says that Christ was the Word and divine.
Bear in mind that Matthew and Luke state that Christ came into existence through the virgin birth.
Christians then debated: in what sense was Christ a divine being? If he was divine, how was he human? This essentially means two gods because one is a divine being and the second is a human being. Jesus is one God and the father is one God, making them two, but yet, Christians stated that they have one God.
Docetism: Other Christians felt that Christ was fully God. But he appeared to be a human being, like an apparition. This view is known as Docetism. However, this view died out because Christians said that if Christ was not human, how could he have died for people’s sins?
Separationism: Another view that gained ground amongst Christians about two hundred years after the Gospels were written was Separationism. These Christians said that Jesus was human and divine. This view states that the divine being came into the human being at the baptism of Jesus. This gives Christ a divine part and a human part. There were parts to him. When the human part died, then the divine part went up to heaven. This was declared a heresy by many Christians.
Modalism: Another view that Christian scholars held was Modalism. This was a widely held view, as was considered a standard view amongst Christians. Church leaders in Rome also held this view. It states that God exists in three modes. Three persons in One; Father, Son, and Holy Spirit. This view also fell out of favor, although some Christians hold this view to this day.
Refutation of Modalism: If a person can be a son of his father, father to his son, and brother to his sister, he cannot be three independent persons as a son, as a father, and a brother. To put it simply, if a person is a father, he cannot be the son he is. Each has to be different. Logically and conceptually they cannot be the same.
Others try to explain modalism to be like the example of water. It can be found in three states: liquid, ice, and steam. But this is not analogous to the idea of a father being his own son and a son being his own father, etc., which is inherently contradictory. We can understand how water can be in different modes, but we cannot understand how something can be in modes that contradict each other.
Trinity: This refers to three individuals who are separate persons who are all God.
Who Devised the Trinity Doctrine?
Tertullian, who converted to Christianity just before AD 200 and defended Christianity prolifically until he died around AD 220, initiated the use of the Latin words Trinitas, persona, and substantia (Trinity, person, and substance or essence).
Tertullian believed in the Trinity. He also believed that the Son and the Holy Spirit were inferior in comparison to the Father because you cannot have two beings that are Almighty. They share might. However, this view was also dealt away with in favor of the view that three beings are God, they are equally God, equally powerful, yet there is one God! This is the mystery of the Trinity. According to Christians, if you claim to understand, you don’t understand.
As we have seen, the Trinity was a later development in history. Early Christians thought that Jesus was made a divine being, i.e., the idea of exaltation. He was exalted. Three hundred years later, Christians said that Jesus was eternally existent and was God.
The Noble Qur’an very strongly denounces the Trinity doctrine, and Muslims should do so too. Sayyiduna ‘Isa ‘alayhi as-salam did not preach it either.
«They have certainly disbelieved who say, “Allah is the third of three.” And there is no god except one God. And if they do not desist from what they are saying, there will surely afflict the disbelievers among them a painful punishment So will they not repent to Allah and seek His forgiveness? And Allah is Forgiving and Merciful»
Bart Erhman Lecture: https://www.youtube.com/watch?v=dLJZaPMoZG4