Catholic Christians, and some other Christians, believe that
the New Testament reveals an order or hierarchy to the
organization of the Church. Catholic Christians also believe
that these orders within the Church constitute a sacrament.
Paul defines the New Testament people chosen to constitute
the order of the leadership of the Church.
2 Timothy 2:2
And what you heard from me through many witnesses
entrust to faithful people who will have the ability to
teach others as well.