The Bible clearly tells us there is only one God. “Hear, O Israel: The LORD our God, the LORD is one” (Deuteronomy 6:4).
A similar verse appears in the 72nd verse of Surah 5. Al-Maida which shuns any idea of any worldly or even heavenly being to be at par with Allah and He alone wields His power over all His creations:
The Hindus while believing in one God, found it strange that one God would manage the countless affairs of the universe and mankind. So they made mini Gods responsible for affairs like health, rain, children, wealth, wind, fire, water etcetera. [1]
Likewise, Christians too taking the advantage of extra ordinary birth of the Christ, call God as Father. The Bible clearly tells us there is only one God. “Hear, O Israel: The LORD our God, the LORD is one” (Deuteronomy 6:4). At the same time, we encounter multiple passages in the Bible that show that the one God consists of more persons. While they believe that The term Trinity is not used in the Bible. Yet they drive implied meaning of verses to stress that one God in three persons is very true. [2]
So while Hindus have specified charter of duties of their associated deities, Christians take all three, that is the Father, the Son and the Holy Spirit, at par with each other. This thus is tantamount to "Shirk" as far teachings of Islam or even that of Torah and Psalms are concerned where there is associate(s) of God, for the God is alone, omnipotent and wield His powers all by Himself. He does not need no one else to run the affairs of the world but He. And if at all Concept of Trinity was true, then why didn't Christ spelt it so in clear and unambiguous words or why the concept of Trinity does not form part of Bible?
( 255 ) Allah - there is no deity except Him, the Ever-Living, the Sustainer of [all] existence. Neither drowsiness overtakes Him nor sleep. To Him belongs whatever is in the heavens and whatever is on the earth. Who is it that can intercede with Him except by His permission? He knows what is [presently] before them and what will be after them, and they encompass not a thing of His knowledge except for what He wills. His Kursi extends over the heavens and the earth, and their preservation tires Him not. And He is the Most High, the Most Great.
In the above quoted verse from Qur'an, God clearly tells mankind that there is no deity except Him and Neither drowsiness overtakes Him nor sleep. That He is awake to watch over whatever happens in His domain, which is the entire Universe, and yet He does not need anyone to administer His domain or "Help Him in doing so."
It may be added here that one of the major causes of Christians reverting to Islam is their doubts over the concept of Trinity for they feel that no one else can be at par or be an associate of One True God. So now we have to decide what logic says and how we decide to accept One True God as all by Himself.
This is a big point to ponder upon without being prejudiced.
Disclaimer: The post is based on the concept of One True God as it appears in Qur'an and all other Divine Scriptures without inclusions of additions which even many people believe that those are based on implied meanings, whereas the Divine Commandments are very concise, clear and direct and these do not leave any ambiguity as to their meaning. The purpose is not to undermine any religion or ideas or concepts but to put across view point based on Divine Commandments as contained in Qur'an and interpretation of Godly concepts of other religions.