The word for natural here is the word Psychikos (Strongs G5591). It is better translated soulish. The soul is the whole invisible part of us. The soul is us. If the soul has no living spirit it is us without God.
"But it is not the spiritual that is first but the natural, and then the spiritual. The first man was from the earth, a man of dust; the second man is from heaven." 1 Corinthians 15:46-47 ESV
This verse is talking about Adam and Christ but it is also talking about us. The soulish man is a dusty man.
It is so easy for any of us to live as the 'soulish man'... it is the most natural thing in the world in fact. We are used to that person. He might not trigger alarms like a stranger would. Our dog doesn't bark at that guy when he comes home.
"The spirit of man is the lamp of the LORD, searching all his innermost parts." Proverbs 20:27 ESV
"But it is the spirit in man, the breath of the Almighty, that makes him understand. It is not the old who are wise, nor the aged who understand what is right." Job 32:8-9 ESV
"Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new." 2 Corinthians 5:17 KJV
A soul that is in Christ is a finished product in the sense that God has added the ingredient that will make everything right... Himself. Once in Christ that old solitary self no longer really exists. The new person who is never alone and will never be forsaken is what we are made to be. God will never leave or forsake a soul that has a spirit. He will see that individual as new and in Christ.
Just like we could not save ourselves before we knew Christ. We can not pull ourselves out of self now. God must do it.
"But the salvation of the righteous [is] of the LORD: [he is] their strength in the time of trouble." Psalms 37:39 KJV
"Our God is a God of salvation, and to GOD, the Lord, belong deliverances from death." Psalms 68:20 ESV
God must pull us out of self. We find mechanisms that allows us to become available for Him to do that.
"For the death he died he died to sin, once for all, but the life he lives he lives to God. So you also must consider yourselves dead to sin and alive to God in Christ Jesus. Let not sin therefore reign in your mortal body, to make you obey its passions. Do not present your members to sin as instruments for unrighteousness, but present yourselves to God as those who have been brought from death to life, and your members to God as instruments for righteousness." Romans 6:10-13 ESV
A person born from above has the right ingredients to live a spiritual life. It is proximity to God that is the issue now. We can live far away and be 'just ourselves'. Lacking and missing something that we can never find or provide... Or we can be close and aglow with the life that come from Christ who Is the Life Giver.
Draw us close today God. Make our solitary self a thing of the past. Fill us with your Spirit. We are sealed by your Spirit but fill us and light us ablaze with your life as we fix our eyes on Your graciousness.