Soul, body and spirit, in a miraculous way, are integrated to sustain the man of life; but the weakest and most limited part is the material expression. When Adam and Eve sinned by disobeying God's precept, the first thing that needed to be hidden and protected was the body; it manifested its dependence on imperfection and death.
They saw themselves naked, because the physical, which is the palpable and demonstrable, recognized its condition of impotence and fragility, as consequences of the infraction of the law; being so, when a decision is presented from the spirit to be intimate with the Creator, the flesh, without having initiated the fulfillment of such order, feels violated and defeated. An example is fasting, which is difficult to perform, but with practice, the body has no other way out but to submit, entering into an agreement so as not to find itself in "danger", since it has its own way of reasoning and understanding.
Matthew 26:41 NKJV
41 Watch and pray, lest you enter into temptation. The spirit indeed is willing, but the flesh is weak.”
Romans 7:18-23 NKJV
18 For I know that in me (that is, in my flesh) nothing good dwells; for to will is present with me, but how to perform what is good I do not find. 19 For the good that I will to do, I do not do; but the evil I will not to do, that I practice. 20 Now if I do what I will not to do, it is no longer I who do it, but sin that dwells in me.
21 I find then a law, that evil is present with me, the one who wills to do good. 22 For I delight in the law of God according to the inward man. 23 But I see another law in my members, warring against the law of my mind, and bringing me into captivity to the law of sin which is in my members.
Mark 9:29 NKJV
29 So He said to them, “This kind can come out by nothing but prayer [a]and fasting.”
2 Corinthians 4:10-11 NKJV
10 always carrying about in the body the dying of the Lord Jesus, that the life of Jesus also may be manifested in our body. 11 For we who live are always delivered to death for Jesus’ sake, that the life of Jesus also may be manifested in our mortal flesh.