Rather than aim to demonstrate the error of other religions,
denominations, or sects, Christians are called to proclaim the truth and
let their light shine. The positive focus will draw others to Christ much
more than a negative demonstration of the ignorance and lostness of those
who do not know God. Still, there is an important place in faith-building
apologetics for studying other systems of beliefs, and I sense in your
question a searching for answers, for boundaries, and perhaps for an
ability to build a bridge with outsiders.
Since your question is about Islam, let me make a couple of
recommendations. First, read the Qur’an. It is only 4/5 the length of the
N.T. and this will help you understand where Muslims are coming from. (I
would probably not aim to read the Qur’an if you have not completely read
the Bible at least once or twice; keep those priorities straight!) As you
read the Qur’an, you’ll easily notice the confusion when it comes to O.T.
and N.T. events. Second, I would like to recommend the best book I have
ever read on Islam, Norman Geisler’s and Abdul Saleeb?s Answering Islam:
The Crescent in the Light of the Cross (Grand Rapids: Baker, 1993).
Dr. Douglas Jacoby