I'll avoid pointing out that Allah is simply the Arabic word for "God" and is also what every Arabic-speaking Christian reads and says when they read the Bible, pray, or go to church. Though I will point out, again, that if the "god" mentioned on American currency is intended to be so utterly vague a concept as to encompass every idea of the divine, it ceases to be meaningful at all.
If the "god" mentioned on American currency is intended to be the God of Abraham, Isaac, and Jacob then it is explicitly exclusionary and amounts to official endorsement of, if not a particular religion, a set of religions. And that emphatically contradicts the founding principles of our republic.
If the only reason someone can think of as to keep it our motto or keep it on our currency is because it makes them feel like they are part of the favored religious class in this country then they should probably take a moment to imagine what it would be like wearing another person's shoes. If you wouldn't like the motto to read, "In Zeus we trust" or "We don't trust any gods" then you should be able to have the basic human ability to empathize with others who find the current motto problematic.
I outlined earlier in this thread why I personally, as a Christian, feel about the motto in regard to my own faith in Holy Trinity. I don't subscribe to a nebulous theistic confession, I subscribe to the historic creeds of the Christian Church which expressly speak of faith in the one God and Father, Maker of heaven and earth, in His only Son, Jesus Christ our Lord, and in the Holy Spirit the Lord and giver of life. The "One God in Trinity and Trinity in Unity, neither confounding the Persons nor dividing the Essence" as it is written in the Quicumque Vult. That's my Christian faith.
I don't need a nebulous flat theistic confession; nor do I need or want a state-sponsored support for my religious convictions. I neither need nor want the State endorsing or depriving my religious convictions. I'm quite capable of believing what I believe without the support or the endorsement of the State.
-CryptoLutheran