Funny, then, that the Crusades were arguments between the two most similar religions… 
Is it easier to argue over a small (but very important) difference in doctrine than to tell the Buddhists (who believe in something completely different) that they are wrong?
<< Why would ONE god try confuse everyone ? >>
I think the problem is that people think of God in anthropomorphic terms. The leap from One God to One Right Path seems (IMHO) to limit God’s powers and God’s mind. There can be many paths that are pleasing to God, and that lead to God.
The different monotheistic religions all assign the same characteristics to the universal One God: perfect justice, perfect mercy, love, etc. The question of what ritual to observe, what beliefs to hold, what acts to do or not do, is left for interpretation by the different religions.
According to Judaism, it’s OK for a non-Jew to be polytheist. It’s not the belief that’s critical, but the actions. Thus, devout Hindus who lead good lives can be on a path to God.
IMHO, God is far more complex and incomprehensible than most organized religions conceive, and there can be many routes through the maze of life that lead to Him. [/sermon}