There is much talk today about how we, despite our theological differences are all really worshipping the same God. Is that true? We might like to think that under all this diversity is really a unity but the fact is that there are some pretty radical differences in the understanding of God. So radical that I do not think we can really affirm wishful slogans like the one above. There is only one true God but many have imagined other gods who are not God, surely not God as he reveals Himself in the Bible.
Another common problem today is to presume that the Biblical insights about God are not really unique but merely borrowed from other ancient cultures. Zeitgeist the movie makes this claim. But the truth is that the Biblical tradition, while having some similarities to other things ancient, departs radically from most ancient and modern philosophies. The Biblical Revelation really IS unique and transcends many Ancient and modern errors.
Here are two videos by Fr. Robert Barron that make these points well.