The first thing to understand is that like all other Descriptives, the Term "True Beliving Messianic", is simply an accurate term that defines a specific set of people, but also a term that many in the world do not understand.
Let us take a look at why this is.
Over the past 2,000 years, since Messiah came to tabernacle with us in the Flesh, many people have wanted to start defining the ways they either believed or did not believe in the Messiah. To this end, simply following the Messiah without having to use Descriptives, starting becoming the norm. But, in truth back when Messiah was with us, a person would say that they simply believed on Messiah or that they followed Messiah.
Because Messiah said - I am the Way, the Truth and the Light, one of the first descriptives people came up with was "Followers of the Way". Although this is a nice descriptive, it surely does not tell us who these people really were.
The Hebrew Term Mashiacheem simply means, "Followers of Messiah or Followers of the Anointed One" and was the term used to descibe the followers of Messiah as written in the Book of Acts where it is said, "They were first called Christians ( actually a truly incorrect term ) in Antioch. What one needs to understand that Antioch was similar to any modern major city of the world and was 99% Pagan. They were not really trying to be endearing to these rabble rousers and the terms used to describe them were more of an insult then a compliment of term of respect.
Since English did not become a Language until around the 5th to 9th centuries, the term Christian could not have been the term used for these Messianic Believers. But as time went on, the Term Christian became accepted in the Catholic/Christian world but became an anathema to the Jews. This should never have been the future by any means.
Today, the Jewish, Catholic and Christian world are divided up into 10s of 1000s of different denominations that all claim to believe and follow either the Old Testament or the Old and New Testaments.
This concept is totally insane as we have only ONE Set of Scriptures given by G-d. So, why can't everyone agree on One Truth? The answer is that everyone wants to create G-d in their own image and not allow G-d to be the creator. Their lips may give G-d the Glory, but their Hearts are very far away.
In the end, we are to learn how to live our lives the way G-d intended and not how we think we should be doing it. Hence and for no better term to come up with, the Term "True Believing Messinic" is simply a way to be able to start explaining how to get back to where G-d wants us to be. True means, true to the Truths of G-d. Beliving means we believe the way we were told to believe and not how we choose to believe. Messianic means we follow the Messiah of the Old and New Testament Scriptures and not other variations that have been and are continually being presented as Truth.
We know the Truth because Studying to Show Ourselves Approved reveals the Truth to us and anyone else who wishes to "Seek ye first the Kingdom of Heaven". In order to understand the Truth, you have to study the Truth. Then you will KNOW what makes anyone think the way they do. Try it, you will like it.
You should never believe anyone until you have done an investigation of the facts. All we do is tell you to go and find out if what we tell you is the Truth. We do not force anything down your throat because that is not how G-d and the Kingdom of Heaven work.
Every journey starts with the first step. You choose whether or not to take a journey. You choose what to study or not study. You choose how serious or diserious you want your relationship with G-d to be. We are only here to help you if you want to understand the Truth as G-d has us present it to you.