Do Muslims understand the story of the Bible?

In much of my dialogue with Muslims, many of which are my friends, I've noticed a common trend... they don't fully grasp the story of the Bible. Now to be fair, not many Christians understand it either and are happy to be cradle Christians the rest of their life. But when it comes to dialogue with our Muslim brothers and sisters its very important to own up to our beliefs beyond the pleasant childhood stories of Jesus and be prepared to defend them.

In a lot of cases when debating, I find that arguments scatter back and fourth between verses of scripture both in the Bible and the Quran. Statements like "well how can Jesus be God if he ate food and went the bathroom?" to "How come Prophet Muhammad married a 9-year old girl?". Honestly these types of debates can go off the charts and lead to a lot of mutual frustration!  My friends, throwing verses out like this doesn't always prove anything, in fact many times words just fall on deaf ears.

Let the Bible speak for itself!

So before getting into the nitty gritty and overly detailed scripture verses; understand the story of salvation.  Understand that it's through God's love that he wishes to redeem the word!  God sent the many prophets to continuously reveal more about himself and correct a fallen people time after time... but God also promised that through the "seed" of the woman the enemy would be crushed and that seed is Jesus Christ.  I can't tell you how often I hear from my Muslim friends that God sent the prophets and they all have the same message, to submit to one God.  OK well we believe that too but there's more to it... you don't simply sum up thousands of years of revelation into one simple sentence!

Here's a question...

After understanding the narrative story of the Bible, how then does the Qur'an actually fit?  How does the Biblical journey through the first covenant with Adam and Eve, through her seed in the bloodline of prophets; how does that story have anything to do with Prophet Muhammad... one who was not in the seed line of God's covenants with Israel?