'Of the Flesh' in the Bible

Ye know how through infirmity of the flesh I preached the gospel unto you at the first.

This I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh.

Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness,

For he that soweth to his flesh shall of the flesh reap corruption; but he that soweth to the Spirit shall of the Spirit reap life everlasting.