'Flesh' in the Bible

Therefore, [when I] was wanting [to do] this, perhaps then was I making use of vacillation? Or was I deciding what I was deciding according to the flesh, in order that with me my "yes" may be "yes" and my "no" [may be] "no" [at the same time]?

For we who are alive [are] continually being handed over to death because of Jesus, in order that the life of Jesus may also be revealed in our mortal flesh.

now I ask [when I] am present [that I will] not [need] to be bold with the confidence [with] which I propose to show boldness toward some who consider us as behaving according to the flesh.

For [although we] are living in the flesh, we do not wage war according to the flesh,

even because of the extraordinary degree of the revelations. Therefore, so that I would not exalt myself, a thorn in the flesh was given to me, a messenger of Satan, in order that it would torment me so that I would not exalt myself.