The Bible does not support the Christian belief in trinity at all. One of the scribes once asked Jesus (pbuh) as to which was the first commandment of all, to which Jesus (pbuh) merely repeated what Moses (pbuh) had said earlier:
"Shama Israelu Adonai Ila Hayno Adonai Ikhad."
This is a Hebrew quotation, which means:
"Hear, O Israel; The Lord our God is one Lord."
[The Bible, Mark 12:29]
It is striking that the basic teachings of the Church such as Trinity and vicarious atonement find no mention in the Bible. In fact, various verses of the Bible point to Jesus’ (pbuh) actual mission, which was to fulfill the law revealed to Prophet Moses (pbuh). Indeed Jesus (pbuh) rejected any suggestions that attributed divinity to him, and explained his miracles as the power of the One True God.
Jesus (pbuh) thus reiterated the message of monotheism that was given by all earlier prophets of Almighty God.
NOTE: All quotations of the Bible are taken from the King James Version.