As Christians we have two worlds available to us:
THE PHYSICAL WORLD into which we were born.
THE SPIRITUAL WORLD into which we were born again.
We spent our early years learning to know and understand our physical world through our senses -- sight, hearing, taste, touch, smell. These sensory perceptions have been our scale of observation for learning how this world works, we feel at home here, we feel we belong.
When we are born again we move into a new and different world, the world where God lives and moves and has His being. Jesus calls us to follow Him into this new environment, strange and foreign to us. But we can't see Jesus to follow Him; we can't touch Him -- physically hang on to His coat-tails so we don't get lost. How then do we find the way?
At this point we must acknowledge a vital truth: Being born again does not give us immediate occupancy in the spiritual world -- at this point it gives us a new perception (sense) with which to perceive and experience this new world that has opened to us. If we try to assess and understand this new environment using our physical senses, we will miss the mark. If we try to use our worldly knowledge to plan our course, we will miss the mark. If we try to use our human emotions to find our way, we will miss the mark. We cannot "think" or "feel" our way to the kingdom of heaven.
"Lean on, trust and be confident in the Lord with all your heart and mind, and do not rely on your own insight or understanding. In all your ways acknowledge Him, and He will direct your paths."
Proverbs 3: 5, 6
Is God asking us to give up living by our senses in the physical world and move out and walk in this new and strange spiritual world on a path we cannot see? Walk in the dark so to speak? EXACTLY! Who would agree to such a thing? Noah did, to name one among many. It was no small thing for Noah to believe God. And it is no small thing for us.
Why should we bother to learn about the spiritual world? I can't answer that question for you. I can only tell you why I did. God spoke to me through His word. He said two things.
One was a promise:
"God Himself has said, I will not in any way fail you nor give you up nor leave you without support, nor in any degree leave you helpless, nor forsake nor let you down. Assuredly not!"
Hebrews 13: 5b, 6
The other was a warning:
"The just shall live by faith and if he draws back and shrinks in fear, My soul has no delight or pleasure in him."
Hebrews 10: 38
And I had to choose "my world".
Out of that vast organization called the world, out of the great mass of individuals belonging to it and involved in it, clean out of all that, God has called us. Thus comes the title "Church" ekklesia, "God's called-out ones". From the midst of the great cosmos God calls one here and one there; and all whom He calls He calls out. There is no such thing as a call from God that is not a call "out of the world".