Jesus never prayed to Allah of the Qur’an. Indeed Jesus would have used the Arameic “Alaha” which shares a similar linguistic root to the Arabic “Allah” but it ALSO does apply to the Hebrew “Elohim”. Similarity in name only does not mean similar God!
While “Allah” is the name used by Muslims for their god (al-ilah), the confusion arises for some Muslims when they hear Arabic speaking people from other religions say that they worship Allah. This is because the name ‘Allah’ also happens to be GENERIC NAME or common noun used to refer to different gods for Arab people just as “school” is a common noun used to refer to different schools. This is the case for the Christians living in Arabic lands, but the IDENTITY of their God is different to the Kaaba one.
Jesus prayed “Abba, Father”. There is no word like ‘Allah-Abba’ or ‘Allah-father'” in Islam. Jesus was praying to the true God of the Torah and Gospel who spiritually is our FATHER (Deuteronomy 32:6, Isaiah 63:16, 64:8, Jeremiah 31:9)
Remember, Allah of the Qur’an, in no way, shape or form (spiritually, literally or metaphorically) is he FATHER to anyone (QS 6:100).
Furthermore, Jesus prayed to the Father as follows:
“I have brought you glory on earth by finishing the work you gave me to do. And now, Father, glorify me in your presence with the glory I HAD WITH YOU BEFORE THE WORLD BEGAN.” (John 17:4-5).
How come Jesus says he was with God BEFORE the world BEGAN? Jesus here is proclaiming to have existed before time itself—in eternity! That is why Jesus is the only one to say “before Abraham I am” (John 8:58) and John the Baptist (even though older than Jesus) however says Jesus existed BEFORE him (John 1:15).
Most importantly, is there any prophet who ever HAD GLORY with God before the world began, before creation? Can Muhammad claim to have had glory with his god of the Kaaba before the world began? That would be shirk, right?
When Arabic-speaking Christians use the word Allah, it is usually used in combination with the word al-Ab. Allah al-Ab means “God the Father,” and this usage is one way Arab Christians differentiate themselves from Muslims and their moon and star god of the idolatrous Black Stone and Kaaba.
In truth, The IDENTITY of Allah is really a mixing of and theft of the identities of other gods into one ☝️god. It is Hubal the moon and star god ☪️, his pagan Kaaba 🕋 and Hajr e aswad (Black stone) mixed with the identity of YAHWEH the true God of Israel (Although YAHWEH, the name which comes from Exodus 3:14-15 “I am who I am”) is not any of Allah’s 99 names!
This is why those who heard of Muhammad’s god accused him QS 38:5. ‘Has he turned (the whole lot of) gods (we worshipped) into One God? Very strange indeed is this thing.’