'Spirits' in the Bible

And of the angels he saith, Who maketh his angels spirits, and his ministers a flame of fire.

Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation?

Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, and live?

To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect,