There are certainly strong feelings about this issue. Unfortunately, there are certain positions that cannot be understood until the basic underlying principles are first understood.

The Bible words it this way:

"Whom shall he teach knowledge? and whom shall he make to understand doctrine? them that are weaned from the milk, and drawn from the breasts. For precept must be upon precept, precept upon precept; line upon line, line upon line; here a little, and there a little: For with stammering lips and another tongue will he speak to this people."

—Isaiah 28:9-11

Here is an example:

How do you explain to someone why putting a fast serial ATA (SATA) hard drive in a computer did not speed up overall disk access time and therefore did not improve the performance of the computer? You may have to explain that the motherboard manufacturer cut corners by putting the SATA controller behind (later in the data stream) a PCI controller which bottlenecks bandwidth.

This does not make much sense to most people who don't know computer internals. There are layers of precepts that you have to understand before you can ever grasp this concept.

You must first know what SATA is and why it is fast. You must also know what PCI is and why it is slow. You must also know how things can be "behind" other things in the data stream. Layer upon layer; Precept upon precept.

In the same way, we know that there are issues in life that cause pain and suffering. A person who does not understand the deeper issues of life may continue to hold simplistic child-like ideas that pain is always bad and pleasure is always good and therefore, this person will draw many simplistic, unbeneficial, and simply untrue conclusions about life—and God—as a result.

An example would be homosexuality.

Without a deeper understanding of the spiritual and psychological implications of this lifestyle, people who practice it cause untold damage to themselves and to many others over the long-term, but because this lifestyle does not show any immediate consequences—just as mercury—people continue to practice it until the damage is deep and irreversible.

So, these deeper issues, such as circumcision, are not explainable to someone who does not already understand the nature of mankind or the physiological effects of changes in our bodies or the nature of God.

There is a lot more to this issue, so those who care and are intellectually honest should research all aspects of it carefully. I would also recommend getting to know yourself—good and bad—as this is the first step to getting to understand everything else, and it's shocking (and sad) how few people live their lives and die without ever gaining these basic understandings of how things really work.

Finally, I would recommend reading the Bible. This is the most amazing book that I've ever seen. Reading it carefully will enable you to see the person in the mirror as never before, and this newly-found knowledge and wisdom can forever change you for the better, if you let it.