'Spirits' in the Bible

Aren't they all serving spirits, sent out to do service for the sake of those who will inherit salvation?

Furthermore, we had the fathers of our flesh to chasten us, and we paid them respect. Shall we not much rather be in subjection to the Father of spirits, and live?

to the general assembly and assembly of the firstborn who are enrolled in heaven, to God the Judge of all, to the spirits of just men made perfect,