'According to the Flesh' in the Bible

When I therefore was thus determined, did I show fickleness? Or the things that I purpose, do I purpose according to the flesh, that with me there should be the "Yes, yes" and the "No, no?"

But I implore you that when I am present I may not have to be bold with the confidence with which I intend on showing against some, who consider us to be walking according to the flesh.

For though we walk in the flesh, we do not wage war according to the flesh;