Calvin: Zeal according to Knowledge

This morning I discovered the following statement from Calvin, which expresses so well the fueling conviction of this blog. Commenting on Acts 18:25 (about Apollos being “fervent in spirit” as he preached), Calvin writes that Apollos

was inflamed with a holy zeal to teach. Doctrine without zeal is either like a sword in the hand of a madman, or else it lies still as cold and without use, or else it serves for vain and wicked boasting. . . . Therefore, that doctrine shall be unsavory which is not joined with zeal. But let us remember that Luke puts the knowledge of the Scripture in the first place, which must be the moderation of zeal, for we know that many are fervent without consideration, as the Jews did rage against the gospel, by reason of a perverse affection which they did bear toward the law. . . . Therefore, let knowledge be present that it may govern zeal.

Knowledge fueling zeal; non-doctrinal zeal, on the other hand, suspicious. Yes!