Now, in order that true religion may shine upon us, we ought to hold that it must take its beginning from heavenly doctrine and that no one can get even the slightest taste of right and sound doctrine unless he be a pupil of Scripture.
Author: John Calvin Source: Institutes, Scripture.
The foundation of true holiness and true Christian worship is the doctrine of the gospel, what we are to believe. So when Christian doctrine is neglected, forsaken, or corrupted, true holiness and worship will also be neglected, forsaken, and corrupted.
There is a direct line that runs from our doctrine to our actions, from what is in our minds to what is in our words and ways... The heart spills over into life. Thoughts of God, and of all else, erupt into acts. The filling of the heart with wise thoughts of God becomes the most important, the most practical, business in the world.
Author: Tom Wells Source: A Vision for Missions, p. 108-109.
We should no more tolerate false doctrine that we would tolerate sin.