It is strange and unfortunate that many people today cannot understand that, while some things Jesus taught were universal, many others were specific to the circumstances, the time, and the people he was talking to. The advice you would give a prostitute is not the same you would give to a banker. The instructions to a poor, primitive, farming community are not the same you would give to people today living in a large city and bombarded with electronic devices of all sorts to distract them from anything significant.

    The true teaching of Jesus are not even known to most, only those limited teachings he delivered in a public setting. His true message was spiritual and, since the spiritual world really doesn't change, remain just as true today as they were then. But the material world does change and has changed quite a bit since Jesus' days on Earth. So it is valid and proper for churches and spiritual schools to adjust the teachings and ceremonies to make them suitable for the current time and current people, but how to do that can be tricky. We have to be careful that we are changing those things which were done for social reasons and not those that were based on universal spiritual truths. 

    Those changes should be made by very spiritual people who know what they are doing, not by intellectuals as has been done with recent rewrites of the Bible, translated from Greek by linguists, historians, and other types of materialistic intellectuals who have no understanding of the spiritual truths that Jesus and the prophets were trying to express as well as possible with the limited ability of language intended to describe material things. Those new  translations are largely nonsense because those doing the translating had no understanding of the spiritual truths hidden in those words so they often eliminated them.