How do we define what is "essential"?

I hear a lot lately of people focusing on the "essentials" of *insert x* whether it be Catholicism, problems in society, or whatever the so called issue of the day may be.

To which I respond: How do we define what is essential? Especially when it comes to our Faith.

In the secular world in particular in my fields of math and physics, this question is easy to solve. The essentials can be defined as those from which without them, you'd be completely lost...For exampe, fi one does not know algebra and trigonometry, calculus would be very difficult. (I don't say impossible, as I'll be teaching my future kids Calculus at age 1 ;)). Another example is in physics without understanding the laws of motion at non relativistic level, one can't extend that concept to the quantum level. There are so many situations by which one has to have a basis from which to begin.

But how can we do with with the Logos, the Word Himself? How do we define essential teachings? To devalue the teaching on the Eucharist causes damages to various other teachings in the Church Universal...This domino effect does not exist as much in the secular disciplines as it does in the teachings of the Church. That is to say one doesn't necessarily go into all of the details of various disciplines in the secular world (hence the idea of majors in university study)

The thing about the Church is that if we decide to de-emphasize something, there are severe consequences when we do that. For example, the Church teaches that the Mass is the unbloody re-presentation of the same Sacrifice on Calvary. (Christ is not re-crucified at Mass, Jesus died once and for all)...in many places the Mass is treated as a glorified social gathering....by doing this we give grave harm to the virtue of Justice in which we give to God what is due unto Him (proper worship, which falls under religion) in exchange for self-idolatry...(Something that Pope Benedict XVI severely warned us against)

The same effect happens for the "red letter" Bibles that place emphasis on the words that Jesus said. What? Is the rest of the Bible not God inspired or not as important? God inspired the whole Bible, not just the words of Christ, although He's the 2nd person of the Blessed Trinity...what are the 1st and the 3rd persons of the Trinity not important? You can see where I'm going with this can you not? That is to say that is to say in the Church, all of Her teachings are important. One can't simply discard them for the sake of an interview, or to be comfortable with someone. The Truth is the Truth, and we need not apologize for it.

Prudence is not the ability to be sissy about the Truth...it is not prudent to not teach the Truths of the Church. It may very well be a matter of respect that one acts according to the rules of the owner, but this is not prudence, it falls under a different category.

Enough with the capitulation of the Truth, we need to speak it whether people want to hear it or not. Whether they get offended, or praise us. The Truth is the Truth, we need to speak it with charity and clearness. Not to eliminate "non-essential things"...all of Her teachings are essential...ALL of them, not one, not two, ALL....just as ALL of Christ is important, not just his human nature, not just his Divine Nature, All of Christ.

Pax Vobis