SPIRITUAL AND PHYSICAL LIFE
Flesh gives birth to flesh, but the Spirit gives birth to Spirit
We can't feel the new birth or the spiritual life with our five senses. We can't see it. The spiritual lif will endure, while the physical life will one day end. Our lives on earth will eventually become like dust, which is blown away and never seen or felt again. Then only the spiritual life will remain. We will be raised from the dead and will come alive once again.
We can't see or understand this spiritual birth. We mst simply believe it. What is born of the Spirit is spiritual, and the primary benefit of this new birth is the forgiveness of sins and eternal life. Nevertheless, Christians still have an external existence. While they live here on earth, they are nurtured by a mother and a father, eat and drink, wear clothes and shoes, have a house and a garden, and own money and property. They view all of this as if they were guests who were traveling through this land to another city - their true destination. When they arrive there, they will no longer care about the places where they stayed along the way. During the journey, they were always thinking, "Today, I am a guest. Tomorrow, I will continue my trip." In the same way, a Christian also thinks, "Today, I am a guest on this earth. I eat and drink here. I live honorably and modesly in this life. But tomorrow, I'll proceed on my way to an eternal life in the kingdom of heaven, where I am a citizen." So Christians also journey through this life. When they come to the end of this life, they will let go of everything physical and enter a spiritual life that will never end.