Ambition is the mother of all heresies

John Calvin on Acts 20:30:

Therefore, ambition is the mother of all heresies. For the sincerity of the word of God doth then flourish when the pastors join hand in hand to bring disciples unto Christ, because this alone is the sound state of the Church, that he be heard alone; wherefore, both the doctrine of salvation must needs be perverted, and also the safety of the flock must needs go to nought, where men be desirous of mastership. And as this place teacheth that almost all corruptions of doctrine flow from the pride of men, so we learn again out of the same that it cannot otherwise be, but that ambitious men will turn away from right purity, and corrupt the word of God. For seeing that the pure and sincere handling of the Scripture tendeth to this end, that Christ alone may have the preeminence, and that men can challenge nothing to themselves, but they shall take so much from the glory of Christ, it followeth that those are corrupters of sound doctrine who are addicted to themselves, and study to advance their own glory, which doth only darken Christ. - John Calvin, Commentary on Acts, vol. 2 at CCEL.

HT: C.K. Barrett