Actually, Christians don't take it literally enough.

First of all, the "devotional" teaching that Jesus was using the word "needle" to represent a small opening in the city wall to enter the city once the gates were closed for the night, is not backed by historical documentation. These small openings in the walls of the city were not built until the 4th Century AD.

Secondly, Jesus used what is called hyperbole in His teachings.  In Matthew 23:24 Jesus used the hyperbole, "straining out the gnat but swallowing the camel" (literal translation).  In Luke 6:41 Jesus used the hyperbole, "but why are you looking at the speck in the eye of your brother, but you do not perceive the log in your own eye?" (literal translation)

Thirdly, the Greek words used to describe the "eye" and the "needle" are very exact and would not allow for any other interpretation than a literal "camel passing through the eye of a needle." This was a popular proverb of the day to express impossibility, as the rabbinical writings used, "It is harder for an Elephant to pass through the eye of a needle," and even the Koran uses the same proverb in the same form that is found in the Bible, "It is easier for a Camel to pass through the eye of a needle."

In Matthew 19:24 the word for "eye" is TRUPAYMA, which means hole, porthole, eye of a needle from TRUPAO, to bore a hole. The word for "needle" is RhAPHIS, which means a sewing needle. So in this text, Jesus was referring to an actual hole in a sewing needle.

In Mark 10:25 the word for "eye" is TRUMALIA, which is related to the word TRUPAYMA in Matthew above and means hole, eye of a needle. The word for "needle" is the same as in Matthew above - RhAPHIS, a sewing needle. Again, this text brings out that Jesus was talking about a literal hole in a literal sewing needle.

In the last text, Luke 18:25, the word for "eye" is TRAYMA, which means an opening, a hole of any kind and is a more general word than in Matthew, but is related to the same word TRUPAYMA. The word for "needle" is the same word used in Matthew and Mark, RhAPHIS, which means a sewing needle. What is interesting about this text is that some older manuscripts use a different word for "needle" here; they use BELONAY, which is a more technical term that means a surgeon's needle. This is interesting in that Luke, who wrote the account in this gospel, was a physician. As with Matthew and Mark, Luke also presents the teaching as referring to a literal "eye" or "opening" of a "sewing needle" or "surgeon's needle."

In summary, Jesus used a proverb well known in His day to illustrate the fact that Salvation is impossible with man. This is brought out by the response to this teaching by the Disciples recorded in Matthew 19:25, "Who then is able to be saved?"  If He was making reference to a hole in the wall that was possible for a man to crawl through, His disciples would have understood that a rich man can crawl into heaven on his knees and they would not have been astonished because they would have understood that He was presenting "Salvation by Works."

Their response demonstrated they understood that Jesus was using the most extreme elements known in that day, a camel - the largest of animals, and the eye of a needle - the smallest of openings, to express that with man salvation is impossible. Then Jesus said in Matthew 19:26, "With men this (salvation) is impossible, but with God all things are possible."