Zeal is not the test of godliness, nor can zeal make one godlier.
Zealousness can even be a detriment to godliness if one’s definition of godliness is derived from the intensity of one’s zeal rather than the clear teaching of Scripture. Frequently we find people who claim to be Christian, and may very well be, zealous about what they believe to be the true priority or expression of the Christian faith.
They often have some scriptures to bolster their defense that their way is the way. But one’s level of zeal is not the determiner of whether something is a legitimate representation of the Christian faith, and this even when the cause is noble.
Godliness drawn from and defined by Scripture should define our zeal, but zeal can never define godliness.
“For I testify about them that they have a zeal for God, but not in accordance with knowledge” (Rom 10:2).