The first man, Adam, was created by God. The last Adam, Jesus, was born of God.

When a person isn’t born of the Holy Spirit, whether Christian or not, they’re just a creation with a worldly nature. That is, a living being, subject to the heart’s misleading impulses. Their emotions will always speak louder than reason.

It’s not important whether or not their smart and capable, their choices will always be influenced by what their feeling, which implies negative results.

But, after being generated by the Holy Spirit, their nature becomes spiritual. They are spirit. They lose their earthly sentimental nature and assume a heavenly spiritual nature.

“Flesh gives birth to flesh, but the Spirit gives birth to spirit.” John 3:6

An Earthly creation is worldly; a heavenly creation is celestial.

There is no middle ground, either they’re worldly or heavenly.

“The first man Adam became a living being; the last Adam, a life-giving spirit.”
I Corinthians 15:45