Think about this. Man is by nature religious. You cannot find a people or culture anywhere under the sun that does not have religion. Man is religious because he is made to be by his Maker for his Maker and religion is man's expression of a desire to know his Maker.
Now think about this. Christianity is spread across the globe. In every culture at every time and in every place where Christianity has been introduced it has taken root. Under every circumstance imaginable, it has thrived. It has thrived in times when it was illegal and punishable by cruel death. It has thrived when and where people had nothing and it has grown and thrived when and where people have wanted for nothing. Christianity seems to be the most indiscrimnate force on the face of the earth. Willing to allow us to avail ourselves of it's truths and beauties regardless of who we are or where we are.
I have to think that this seemingly universal call of Christianity owes to the fact that it is the fullest and truest expression of our desire to know GOD and GOD'S desire for us to seek Him. In other words, Christianity fits all of us, universally like nothing else on the face of the earth, because it is made for us by the Maker who knows how to make something that fits us.