Belief in One God is as intrinsic and integral to the Christian faith as it is to Judaism and Islam. But none of the three has yet arrived at accountable belief in the One God of All.
Each is to some extent still caught in the ephemeral cultural traps and trappings in which the scriptures and traditions of each were written.
And each has remained in its comfort zone of henotheism, belief in its particular view of God, falling well short of true monotheism, which recognizes that God is incomprehensible.
Some adherents of Christianity falsely think that some of those cultural trappings are traits of monotheism, such as patriarchalism and the honor-shame syndrome on which nearly all societies are and have been structured, and some have worked to eliminate the trappings but kept henotheism intact, or worse, have foolishly toyed with the chaos of polytheism.
Belief in the One God of All has at best been held out, like the coming of Messiah or the Second Coming of Christ, as a goal to which to aspire while calling common belief in the One God of All unrealistic and unattainable.
It is our contention, on the contrary, that the time has come for all three religions to work out what belief in the integrity of reality and of all humanity really means in contemporary terms and to strive to make that belief a reality if humanity is to survive the twenty-first century.-- James A. Sanders, Paul E. Capetz
Credo in Unum Deum: A Challenge
Biblical Theology Bulletin: A Journal of Bible and Theology, Vol. 39, No. 4, 204-213 (2009)