'Of the Flesh' in the Bible

but ye know that through weakness of the flesh I proclaimed the Gospel to you formerly;

But I say, walk by the Spirit, and ye will not fulfill the desire of the flesh.

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

because he that sows to his flesh shall of the flesh reap corruption; but he that sows to the Spirit shall of the Spirit reap life eternal.