Jesus is speaking of devotion to the Supreme Being. He says this just after he says:
"In the same way, those of you who do not give up everything you have cannot be my disciples." (Luke 14:33)The process of giving up something for something else is called devotion. Devotion is a natural part of our constitution. By nature, we must be devoted to something. Why?
Devotion means making a choice with ones life.
One can devote ones life towards becoming famous or winning at some sport or skill. Or one can devote ones life towards becoming a leading politician. Or one can devote ones life towards having a big family and a big house. Or one can devote ones life towards becoming wealthy. Or perhaps one can devote ones life towards reaching all of these or a combination of these things all at once.
To achieve any or a combination of these things means giving up other things. A person who wants to have a big family and big house will have to give up the singles life of dating around. The person who wants to be a leading politician must give up those activities that will lose elections. To achieve wealth one must give up spending money frivolously. Accomplishing each of these requires giving up something else.
Spiritual life is no different.
Spiritual perfection also requires the same process of giving something up. When Jesus says "everything" he is referring to all our attachments to the physical world - our temporary body and that which is connected to our temporary physical body.
Jesus communicated this same instruction elsewhere:
“No one can serve two masters. Either you will hate the one and love the other, or you will be devoted to the one and despise the other. You cannot serve both God and money." (Matt. 6:24)"Money" in this statement is translated from the Greek word μαμωνᾶς (mamōnas), which is more appropriately translated to "mammon" or "materialism."
The reason one cannot serve materialism and God at the same time is because each requires devotion in order to serve them. Materialism comes with many requirements - time, dedication to gaining that object of materialism (especially money), and attachment to it in order to maintain that object of materialism.
Being devoted to materialism renders ones existence meaningless - as Jesus states above.
Materialism comes with three forms of anxiety:
- The anxiety of not having what we desire and the possibility of not getting it
- The anxiety of losing what we have already achieved or gained
- The anxiety of having lost what we had previously
These three anxieties pertain specifically of materialism and this is based upon the fact that we are not these physical bodies. And because we are not these physical bodies, the objects of materialism are fleeting and temporary. They come and go. One might have money one day but then lose it in the future. One might have a big house but one day the bank forecloses on it. One might have a big family but at some point the kids grow older and go their own way, leaving the 'empty nest.'
Then, even what we might retain to the end of our life, we lose it at the time of death. When our body dies, we must leave behind everything in the physical world. Any money, homes, family, careers, reputation - everything - we might still have, will have to leave behind at the time of death.
This is because these physical bodies are not us.
Each of us is a spiritual entity who temporarily occupies a physical body. At the time of death we leave these physical bodies behind and everything they may possess.
But our spiritual person must still - by constitution - embrace something or someone. Our desire to devote ourselves to someone or something remains. This is not a composition of the body. This part of the spirit-person's composition. By constitution the spirit-person is active, and by nature, must be devoted to something or someone.
For this reason, a spirit-person who leaves the physical body while remaining attached to the things and people of the physical world will come to occupy another physical body in the physical world in order to achieve those. This is the design of the Supreme Being, as He lovingly allows the spirit-person to live out ones desires.
For this reason, materialistic family members typically rejoin each other in subsequent lifetimes - albeit typically within a different relationship and without knowing how they knew each other in a previous lifetime. And depending upon how they lived their lives, this may not even be within a human family. It may be within another species of life depending upon the consciousness and activities of the family members during this lifetime.
This is because God's design also requires that we must deal with the consequences of our activities - in order to learn. This means the next lifetime will also embrace whatever we did in this lifetime. If we hurt others in this lifetime, we will receive that in our next lifetime. This is why, for example, children can be born into suffering. This is the result of that spirit-person's actions in a previous lifetime in another body. (This doesn't mean we can't help such a person, however. Mercy is also part of our learning process.)
But for the spirit-person who becomes devoted to the Supreme Being - when that spirit-person leaves the physical body, they won't return to the physical world. Devotion to the Supreme Being allows them to return to our real family in our spiritual home in the spiritual realm.
But in order to achieve this according to Jesus, we must become dedicated. We must be prepared to give up our self-centered goals of materialism and live for the Supreme Being. We must dedicate our lives - first to coming to know God, then to establishing a devotional relationship with Him, and then to becoming pleasing to Him.
This doesn't mean we have to give up our job or our career or our family or our possessions. But it does mean giving up the notion that these things will make us happy. We have to give up our attachment to them, because after all, we will lose all of them anyway.
In such a state of dedication - we can devote whatever things we have to the Supreme Being as well. Anything within our realm of influence can be devoted. Whatever we may temporarily have can be offered in ones service to the Supreme Being. And instead of seeking praise for ourselves, we can praise the Supreme Being.
And once we offer to Him the things we might temporarily have in the physical world, those things will belong to God. And instead of our life being an instrument for materialism, our life can become His instrument - giving us the facility to enter His world and come to know and love Him with all our hearts. In this way, we can achieve our innate "saltiness" - our natural position of loving devotion to the Supreme Being.
This is the goal of Jesus' teachings - to come to love God with all of our hearts:
" ‘Love the Lord your God with all your heart and with all your soul and with all your strength and with all your mind’" (Luke 14:33)