'Servants' in the Bible

who also made us sufficient as servants of a new covenant; not of the letter, but of the Spirit. For the letter kills, but the Spirit gives life.

For we don't preach ourselves, but Christ Jesus as Lord, and ourselves as your servants for Jesus' sake;

but in everything commending ourselves, as servants of God, in great endurance, in afflictions, in hardships, in distresses,

It is no great thing therefore if his servants also masquerade as servants of righteousness, whose end will be according to their works.

Are they servants of Christ? (I speak as one beside himself) I am more so; in labors more abundantly, in prisons more abundantly, in stripes above measure, in deaths often.