This word occurs often in the N.T. It stands in contrast to what is earthly, Ro 15:27; and to what is carnal, or of the flesh. 1Co 3:1. In short it may be said to be that which is of the Holy Spirit, in contrast to what is of the natural man.
Yes, it has been their good pleasure; and they are in their debt. For if the Gentiles have had a part in the things of the Spirit which were theirs, it is right for them, in the same way, to give them help in the things of the flesh.
And the teaching I gave you, my brothers, was such as I was able to give, not to those who have the Spirit, but to those who are still in the flesh, even to children in Christ.
Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain