for this reason many are weak & sickly

​Why many believers are sick.
In 1 Corinthians 11:18-34, Paul talks about division among the believers, something that still exists today where different groups have different ideas of what it means to believe and follow Christ. He used eating together as an analogy of coming together just as Jesus used eating bread and wine as an analogy to partake in the gospel. Let's break this down:
 
Paul starts in verse 18-22 by remarking that when they come together, there are different cliques; some are genuine about following Jesus and some who come for free food. This coming together to eat, is not what Jesus was talking about before His death. To Paul, this coming together as a church and partaking of the food has become a contentious affair as some look down on others or judge others who cannot afford to bring their share of food. It is also an analogy for people who are coming for a 'free-ride' to Christs' eternal kingdom where going to church is seen as a mark of being a Christian rather than repenting from an old life, following Jesus and transforming to become Christ-like.
 
Paul then explains what Jesus was actually saying at the last supper; that when the disciples broke bread and shared wine with Jesus, they were eating with Him the same bread and wine symbolising that, should they see their purpose through in their lifetime, they would be partaking in the same suffering and blessings of the walk as Jesus. When Jesus lived, He performed signs and wonders to show that God is real and was persecuted. Those who ate with Him that day also did the same; they performed signs and wonders and were persecuted, all except Judas, who betrayed him. Judas symbolises the one who partook of the bread and wine unworthily. (Verse 23-25)
 
Every time the church gathers together to partake of the gospel (or food), she is meant to remember Jesus, that He died for us and is the reason we have the chance for a new life with a new heart and a new behaviour. When you step into church, you are meant to have self-examined through the week if you would be worthy of partaking of today's food (or the gospel) and worthy of being part of Christ's church. (Verse 26-28) What did you do in the week before you came to church? Did you tell a white lie to your parents or spouse? Did you cheat your employer of 10 minutes of their time? Did you create trouble for someone, or did you keep your peace? Did you love your neighbour or just loved yourself?
 
Paul is emphasising that coming to church to eat together, is not about eating food but about eating the bread and wine of Christ worthy of His death, worthy of His blood upon your life. In verse 29-30 Paul explains that anyone who comes to gather in church to eat (the gospel) yet did all the things that were unworthy of the cleansing from the blood of Jesus in the week before, not discerning his own wrong deeds, would end up being sick and sometimes die.
 
'For this cause many are weak and sickly among you, and many sleep' - 1 Corinthians 11:30
 
Brother and sisters, now you understand why your brothers and sisters are sick, share this message with them so that they might confess their wrongdoings, ask for forgiveness, change their ways and start again. By God's grace and the blood of Christ, we can still repent and get back on course to transforming and becoming fruitful for the kingdom.
 
That ye might walk worthy of the Lord unto all pleasing, being fruitful in every good work, and increasing in the knowledge of God; -Colossians 1:10