'Servant' in the Bible

Who are you to judge the servant of another? To his own master he stands or falls; and he will stand, for the Lord is able to make him stand.

For I say that Christ has become a servant to the circumcision on behalf of the truth of God to confirm the promises given to the fathers,

I commend to you our sister Phoebe, who is a servant of the church which is at Cenchrea;