>Whether you call it ceremonial or not, it is part of the law, right?

It doesn't appear you understand the law and what Jesus meant by "fulfilling" it. What does your dictionary say that "fulfill" means? In essense, it means to "satisfy."

>Now, the central part of the Teachings is unaltered, and perhaps that is what you mean. For instance, in the Old Testament it was not considered proper to kill people, and that part was maintained.

Actually, the act of "murder" (not killing) was forbidden. Exodus 21:23 lists a time to kill.

>Other laws had to change according to the requirement of the times.

You're speaking too much in unsupported generalities. I cannot agree with this. What is your interpretation of Matthew 5:18 and Luke 16:17, which to me means the law does not change?

>I find it quite logical that God reveals certain laws, and then changes them later, according to the changing needs of society.

You are basically putting God in a box, and that's very dangerous. God does not have to be percieved as logical because some things are not fully revealed to us.