There is an absolute truth. Absolute truth. Simply stated, absolute truth is true for everyone, anywhere on earth at any time. And there are some absolute truths that would apply to human beings anywhere in the universe. One example of an absolute truth that would apply to human beings anywhere in the universe would be that all humans will eventually die, no matter how long they may live or how healthy they may be currently.
Facts are pieces of information, situations or things that are known to be true, and have people who can witness to and attest that they are in fact, true, but they only apply to certain persons or certain specific situations and are not necessarily true for everyone, anywhere at anytime.
Knowledge may be neither true nor factual. Knowledge is subject to change and correction. For example, 50 years ago, there were many things about medicine and science that were "known" to be true. Things that many thousands or millions of people had knowledge of, that in fact, many years later, were eventually found to be changing over time. Science and medicine fall into this category.
Scientific knowledge has changed dramatically over the last 100 years, and has doubled again in just the last few years. Medical knowledge has changed dramatically as well. But in those worlds the information is constantly changing and updating as technology and knowledge increase. Absolute truth does not change or need to be altered at any time. Absolute truth is always true no matter what, no matter who.
Most of the war and strife in the world today is the result of knowledge or supposed "facts" that people accept as absolute truth. No matter how many political parties there are, no matter how many organized religions there may be, no matter how many separate denominations within those religions, the disagreement and strife comes in because people are supposing knowledge or some set of facts to be truth. When, in fact, they are not. Just because we believe something does not make it true. The truth is absolute, but often obscured and covered up by knowledge. There can only be one real, absolute truth, but there can be many versions of the "facts" or knowledge about various religions.