Non-Muslims have the right to find contradiction in the Quran and Muslims are obliged to answer them. We just need well-spirited and open-minded dialogue. I came to believe in Islam the hard way by trying to examine potential flaws and contradictions. I picked this alleged contradiction from a skeptic web site:
Who was the first Muslim?
The same did Abraham enjoin upon his sons, and also Jacob, (saying): O my sons! Lo! Allah hath chosen for you the (true) religion; therefore die not save as men who have surrendered (unto Him).
And Moses fell down senseless. And when he woke he said: Glory unto Thee! I turn unto Thee repentant, and I am the first of (true) believers.
And I [Muhammad] am commanded to be the first of those who are Muslims (surrender unto Him).
My answer: Muslim in Quran is the one who submits to God. If you submit at the time of Abraham to his message you are a Muslim. If you submit at the time of Moses you are a Muslim and so on. The first to submit to God at the time of Abraham (PBUH) is Abraham himself, the first to submit at time of Moses (PBUH) is Moses and the first to submit at time of Muhammad (PBUH) is Muhammad. The first to submit to the Torah by definition is Moses and the first to submit to Quran is Muhammad.