New Spirit or Renovated Spirit
New Spirit or Renovated Spirit
For me heart and spirit are very closely related. Our spirit is the life force. It's who we are as a being. Then we have a soul (mind, will, emotions) which comprises our personality. As used in scripture, “heart” can refer to either or both. Our deepest desires and motives are wrapped up in the idea of the heart, so it's very much about our personality. Yet heart is also sometimes used synonymously with spirit.
We read that we have been crucified with Christ (Galatians 2:20) and that old us died with Christ (Romans 6:6). We also have the promise from Ezekiel that Father will remove our cold hard heart and give us a new soft heart, and that He will give us a new spirit and put His Spirit within us.
Those things all point to complete recreation, as we read about in 2 Corinthians 5:17.
There are a couple of passages, like Psalm 51, where we read things like "renew a right spirit within me." I think that is because the idea of spiritual rebirth was as yet unknown, since Holy Spirit had not yet come to live in people.
So, my belief is that we got a new spirit. That requires God, because only He could replace us completely while maintaining our identity as a person. Jesus said that God could create children for Abraham from stones. I think that's similar to what He did to us.
Another thing I find helpful in thinking about this, is that death (spiritual death) is relational separation from God—the source and sustainer of life.
The dry bones metaphor from Ezekiel 37 and our earthy idea of death only goes so far in describing that.
I think our old self and our human spirit are the same thing and the death of that is what removes us from Adam’s lineage and thus frees us to be reborn of the Spirit.
I think it is wise for us to be humble about this though. His ways are higher than our ways and His thoughts than our thoughts. There’s a lot we are simply not equipped to understand.