Several months ago, I got what I think is an analogy with which to describe the message of communion… For some reason, this is the right time for me to “write it down.” 
1 Corinthians 11:28-30 states: “A man ought to examine himself before he eats of the bread and drinks of the cup. For anyone who eats and drinks without recognizing the body of the Lord eats and drinks judgement on himself. That is why many among you are weak and sick, and a number of you have fallen asleep.” 
Being a nurse for a little while, I have had the job and opportunity of working in the hospital with “sick” people. In other words, individuals with ailments, illnesses, diseases, which are highly contagious. In order to provide proper care for my patients, I am required to be healthy myself. By law, by whatever hospital administration I am under, and by my own standards because i believe a sick person can’t properly care for another sick person; neither should either of them be exposed to further disease. In order for me to deal with those who are hurting and provide palliative support, comfort measures, or assist in the administration of necessary medicines, I must take the highest precautions in cleanliness, hygiene, infection control and isolation precautions when deemed necessary. Prior to exposure to my patients or vice versa, there are multiple vaccinations I am required to have gotten. The purpose of those vaccinations is to provide a pre-ceding form of protection to me, from the potentially dangerous environment of bacteria, viruses and infective biological agents in the hospital and in those individuals for whom i may be caring. People get sick and may die from a disease caused by infection from a bacterium or virus if they have not been exposed to it before and/or if their immune systems are not effectively strong enough in destroying the antigen that caused the problem. Basically, the antigen was too powerful for the individual’s immune system and overpowered it. That becomes a sickness for which an individual needs expedient treatment.
 A vaccination is quite a genius solution to many biologic problems because it ironically also exposes one to an antigen. The difference however, is that it exposes one to the weakened, nearly destroyed form of the antigen which most immune systems can easily overcome. And if the immune system functions properly, it does what it should: it catalogues and remembers that antigen so if the immune system is ever again exposed to it, its weapons of combating it are ready to go and it is aware of how to overcome the pathogen. So a nurse is required to be immunized before working in a hospital. 
For example, if I am to be exposed to patients with disease A, I need to have gotten the vaccine to disease A. In other words, prior to dealing with the uninhibited, uncontrolled strength of pathogen A, i’ve been exposed to it in its weak form, developed immunity to it over a period of time, and can now deal with it more easily than someone who is not immunized. 
If someone who has not had the vaccination to disease A comes into the area where a virulent disease A is contagious and gets it, they will simply become sick and end up being another patient; unlike me, whose body already knows how to battle it. So I can be the nurse, rather than a patient.

(Ok… I hope you’re still with me, lol)
To explain the scripture we read earlier, partaking in communion is like partaking in the work and body of Jesus Christ. Partaking in the power of who He is and all he represents. His power, His redemption, His glory, His everything that He has given us… The thing however, is that no one can partake of Christ unworthily, As much as God is loving, gentle, kind in His nature, His properties involve being a consuming fire and unless we approach God with the proper protection and precaution, our sin and unholiness makes us as vulnerable to being destroyed by God’s holiness as a piece of paper would to a blazing fire. God wants to draw us close and fellowship with us, but only after we have followed the protocol of becoming protected enough not to be incinerated automatically by who He is which is fully incompatible with all the forms of unrighteousness we naturally exude. 
Before we can minister to others about how to deal with God or partake in the great things He offers, we must ourselves have partaken of it; of Him. But more importantly to note is that we partake of the broken body and shed blood of Christ in communion; the “weakened form” of God Himself. Not the virulent, deadly form of Him which is His consuming fire side. When we partake of his broken body, we take on the vaccine of God. Our spiritual immune system learns how to deal properly with God so we are not consumed. And in so-doing, the greater, stronger side of God becomes more accessible to us to encounter; although never in its entirety because we still cannot fathom the depths of God! 

But to continue, a person who comes and partakes of communion unworthily, or basically without recognizing the body of Christ and having become a part of Him does harm to themselves. Why? Because they just expose themselves to the harmful, fire part of God which they are not adequately prepared to handle. The uninhibited form of the virus; which rather than strengthening them and immunizing them for future encounters, disables and can destroy them completely simply because they are not strong enough to handle it. 

So when the bible says we should examine ourselves before we eat of the bread and drink of the cup, it is right. It’s like asking a nurse to get titers done for a disease, examinining him/herself to ensure that he/she has the immunity necessary to deal with what they’re about to encounter. They actually take IN the virus. How ironic that the cure is in taking it… Verse 31 of 1 Corinthians 11 says “for if we judged ourselves, we would not come under judgement.” In other words, if we judged ourselves by getting the vaccine, subjecting ourselves to the virus & temporarily suffering with light symptoms of the disease but overcoming it, we would not later be judged by unpreparedly meeting with its fierce form which could destroy our weak bodies. 
So if you have come under the Lord Jesus Christ, given him your life, and become one of His own, thereby partaking of the cross: the weakened form of Jesus Christ and getting the boosters of communion with Him which make you stronger, you don’t have to encounter Him uninhibited and die because you finally realize you couldn’t handle him. He is Holy. He is deadly to those who haven’t gotten the protection of He Himself… 

I pray this helps your understanding in some way or the other… I have to stop here…I’m exhausted for now… 🙂 God bless you ….