Recently, while I was speaking, a man in the audience made the assertion that, "We shouldn't make comparisons with other religions, we should just preach the Gospel"
While, I understand his sentiment, I disagree. Why?
Comparison is a powerful teaching tool!!!
When I attended college, one of my professors used the approach of "compare and contrast" on many of the tests. This was very effective because you had to think and understand more deeply in order to explain what was the same and what was different.
Often people think they understand the Gospel or passages in the Bible, but when pressed by other ideas, they are unsure of how to defend or explain their belief. If you don't know the difference between how Christians and Muslims understand 'mercy', you may be led astray by fine sounding arguments. (see Colossians 2:2-4)
Much of the New Testament consists of Paul and others defending Christianity and the Gospel against other ideas and religions. Christianity and other religions, as a whole, are mutually exclusive, despite some similarities.