It is Biblically supported. All the groundwork of understanding can be found throughout the Bible. The Bible speaks of death and life in terms of the state of the spirit.
Gen 6:3 Basically states that we live a finite time and the spirit, our spirit, which contains the complete essence of who we have been begins its return to God. This confirms what others have been saying and have been trying to get across to you.
The spirit is never a reference to breath, literally breathing, unless a metaphor is being used to refer to breath as life and this life is then referring to the life of the spirit. Genesis is about the journey of the human spirit, a journey every one of us must take. Breathing oxygen is so far off from understanding that I can't believe it's you arguing for it.
You've missed the point completely, it's all been said the rest is up to you.
