Leviticus 17:11 tells us that "the life is in the blood". To God, all LIFE is sacred, regardless of what kind it is.
There's more than one kind of life. There's the life that's in the blood which keeps our flesh going ... then there's the Life that the Word of God feeds our spirit man and keeps it alive. The Word, God's Truth, goes into our spirit heart where the "God things" are stored so that we can draw on them anytime.
We still have the old sinful nature we had before we were born again. Where is the place that this old nature lives? It's in our flesh ... containing the lusts of our flesh. So our flesh man is always talking to our soul man, trying to convince it to do what it wants to do. It screams at us: "I'm not going to fast ... I'm HUNGRY!" Are we going to obey our spirit man or obey our flesh?
The sin nature dwells in our flesh. But we don't live there anymore ... we are now a new spirit. We have a soul, and this is where our will is. When we yield ourself to our flesh, we are being "carnally minded". Romans, chapter 8, talks about being carnally minded.
Romans 8:5-8 NKJV ... Those who walk according to the flesh set their minds on the things of the flesh. To be carnally (fleshly) minded is death. The carnal mind is enmity (enemy) against God, for it is not subject to the law of God, nor indeed can be. So then, those who are in the flesh cannot please God.
We have to deal with our flesh, we have to keep it alive or we'd leave (die). But we don't have to yield to the lusts of the flesh ... to obey its wants and desires ... above what the spiritual man desires. We need to go with what the spirit desires everytime ... we do not want to be enemies with God.
Reverend Robert W. & Mary C. Butler