The Arabic word Allah comes from al-ilah meaning "the God." It has the same meaning as Alah or Alaha in Aramaic. Christians had used the word Allah before the time of Muhammad when they worshipped in Arabic and Alah in Aramaic as Jesus is Allah. Thus, the word Allah should be used by Christian as well when referring to the Creator.
“Say, ‘We believe in the revelation which has come down to us and in that which came down to you; Our Allah and your Allah is one; and it is to Him we bow’” (Quran 29:46). “No change can there be in the words of Allah” (Quran 10:64). “We have, without doubt, sent down the Message; and We will assuredly guard it (from corruption)” (Quran 15:9). Thus, in the Quran, Allah proclaimed Himself as the God of the Bible. Allah proclaimed the Bible as His revelation. In the Quran, Allah always, without exception, confirms the Bible as His revelation, unalterable, and protected by Allah Himself. Only kafir would deny it. As the Book of Allah, it is only reasonable that the Bible uses the word Allah.
Aramaic Syrian Christians at the time of Muhammad called Jesus as Rahmana in their invocation “Bismilalaha Rahmana Rhima” that became the “Bismillah Ar-Rahman Ar-Rahim” meaning “In the name of God, the Most Gracious, the Most Merciful” that starts every chapter of the Quran except the jihad chapter 9. Such Aramaic invocation predated Islam itself. FYI: according to the Bible we are saved by Grace through Jesus, not by our own works but as a gift. Then, we are transformed by Mercy through the Holy Spirit (Titus 3:4-8, Eph 2:7-8). Truth and Grace came through Jesus (John 1:17). He is the Grace of Allah. Quran 19:87, 17:110 25:59-60, 43:45, 20:108-109, 19:18-21 proclaim that the only intercession is through Ar-Rahman just as Jesus is the only Intercessor according to the Bible. Thus, we can say “In the name of God the Father, the Most Gracious Son, the Most Merciful Holy Spirit.”
But does the Quran proclaim Jesus as Allah?
1) According to the Quran, Jesus is more than a prophet: Quran 4:171 says, “Christ Jesus the son of Mary was an apostle of Allah, and His Word, which He bestowed on Mary, and a spirit proceeding from Him: so believe in Allah and His apostles. Say not ‘Trinity’ desist: it will be better for you: for Allah is one Allah. Thus, Allah, His Word Jesus, and His Spirit are one. The Trinity in the Quran refers to Allah, His Word, and Mary (Quran 5:117), and thus is false, but who would argue with Allah that Allah, His Word, and His Spirit are one?
2) “If thou wert in doubt as to what We have revealed unto thee, then ask those who have been reading the Book from before thee” (Quran 10:94). Thus if we submit to Allah, we must use the Bible to clarify the Quran instead of using false books or false teachings of men who reject Allah’s words. To be a Muslim, we need to read the Bible no matter what obstacles Allah enemies put in front of us. I would recommend NKJV (New King James translation) of the Bible.
3) Jesus said, “the LORD our God , the LORD is one” (Mark 12:29, NKJV). The Hebrew word for LORD (TUHAN in Malaysia in capital letters is YHVH (vs. Lord (Tuhan) meaning Master). Hebrew Alphabet Charts in the internet such as at http://www.amerisoftinc.com/hebletr1.htm translate the tetragram YHVH as “Hand Revealed Nail Revealed”; i.e. Jesus. The Old Testament Malachi 3:17 proclaims that we are saved by fearing Him and meditating on His name, which is YHVH. Thus, in both the Old and New Testaments we are saved through Jesus, known as YHVH.
4) John 1:1-4, 14, NKJV proclaims, “In the beginning was the Word (Jesus), and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through Him, and without Him nothing was made that was made. … And the Word became flesh and dwelt among us” (comment added in parenthesis). Thus, Jesus was the Word of Allah who came to earth. He is the creative power of God and through Him God created all things including His own body upon coming to the earth. To say that Allah who created the heavens and the earth, animals and mankind, has no power to come down in the flesh is kafir, disbelieving in the power of Allah.
Genesis 1:1 proclaims, “In the beginning God AT created the heavens and the earth.” The two letter Hebrew word AT was not translated nor put into English Bible. Alef is letter number 1 (first) and Taf is letter number 22 (last) in the 22-letter Hebrew alphabet chart. Thus, the full translation should have been “In the beginning God AlphaOmega created the heavens and the earth.” God AlphaOmega is Jesus (Rev 1:8).
5) The term Son of God often confuse people. The term the Son of New York does not mean you are the child of New York. The Bible and Quran agree that God did not marry Mary and had a child because the Word was in the beginning with God and He was God and God is one. As Jesus says, “Before Abraham was, I AM” (John 8:58). The Hebrew word for “I AM” is YHVH just as Allah revealed His name to Moses as “I AM WHO I AM” (Ex 3:14). In fact in Genesis 18, in Mamre, YHVH, later on known as Jesus, visited Abraham and promised him Isaac through Sarah, who was barren and past child bearing age.
The words Allah and God are titles, similar to the words the President or the Secretary, but Allah’s name is YHVH as Allah in the Quran proclaims Himself as the God of the Bible.
The Messiah/Christ is God in the Person. As Isaiah 9:6 says: He is “a child … Prince of Peace … Mighty God.” The term Son of God simply emphasizes the divine nature of the Messiah and the term Son of Man simply emphasizes the human nature of the Messiah.
God the Father, the Most Gracious Jesus, and the Most Merciful Holy Spirit is one and yet distinguishable. Just as you, your word and your spirit are logically one, God, His Word, and His Spirit are logically one.
The name of Muhammad's father was Abdullah meaning the Servant of Allah. Thus, the word Allah itself predated Islam.
The title Allah means God in countries such as Malaysia and Indonesia as they have assimilated this Arabic word into their own languages.
The Bible is the Book of Allah, sealed by Allah in the Quran and should continue to use the word Allah as the title for our Creator vs. the word Tuhan which is equivalent to Lord, and the word TUHAN which is equivalent to LORD in English. Christians had already used the word Allah in Arabic and Alah in Aramaic to refer to Jesus even before Muhammad was born.