You say they intend to pray to the God of Abraham and therefore they are praying to the God of Abraham. That does not make sense to me.
Why not? What else would determine who it is they’re praying to, if not who they intend to pray to? Again, no one here - and certainly not Catholic teaching - denies that they are in grievous error over their rejection of the Trinity and the divinity of Christ. That just shows they don’t fully know the God they pray to.
Why wouldn’t the same principle apply to praying with Muslims?
Receiving the Holy Eucharist requires total unity. Praying with others is definitely not on the same level.
For instance, Protestants are welcome to attend and participate in Holy Mass, but they cannot receive Communion. Also, Catholics can - for just reason - attend a Protestant service but may not receive their communion. See? Different standards apply.
Does St Paul indicate that it is not necessary to believe in Christ or the Holy Spirit?
Necessary for what? Of course it’s necessary for salvation, but is it necessary for God to hear one’s prayers?
Muslims do not pray to the Trinitarian God. Hence, they are not praying to the one true God.
I know I’m repeating myself, but Muslims
are praying to the Trinitarian God even though they don’t realize it and think they aren’t, because the One True God *is *Triune.
I would like to stir things up over this point

**As Christians we beleve that God (of Abraham) inspired Holy Scripture.
Muslims believe the koran to be inspired by Allah
Are God and Allah the same? (As you are obviously convinced they are)
**
Consider this.
The Bible tells us that God sent His only Begotten Son, Jesus, to save the world.
The koran states " …it is not worthy of Allah that He should take to Himself a son" Sura 19: 88-92
God begot a Son. Allah did not. Hmmm.
There is a lie somewhere
As a Catholic I wholeheartedly believe that our Bible was inspired by God. And God cannot and does NOT lie. Therefore the lie is in the koran.
The father of all lies is Satan. The koran (inspired by Allah) contains this lie.
Therefore the koran is inspired by Satan.aka Allah.
So NO! GOD and Allah are Not the same God.
They may believe in one god but he is in no wise the One True God.
Peace be with you
Francis
“Allah” is not a name. It is the Arabic word for “God,” so Arabic-speaking Christians pray to “Allah” as well. Thus much of your reply is nonsense: you’re saying things like, “God begot a Son. God did not. Hmmm,” and “God and God are Not the same God.”
The lie
is in the Qur’an, because God
does have a Son. Muslims mistakenly think God, in whom they believe and to whom they pray, has no Son and they are wrong. It’s just that simple.
By the way, Francis, you do know that the Catholic Church authoritatively teaches (CCC 841) that Muslims and Christians worship the same God, right? CCC 841 quotes
Lumen Gentium, which is from an ecumenical council. You really can’t get any more authoritative than that.