The Human heart is an idol factory.
Faith alone saves, but the faith that saves is not alone.
The blindness of unbelievers in no way detracts from the clarity of the gospel; the sun is no less bright because blind men do not perceive its light.
It would be the height of absurdity to label ignorance tempered by humility "faith"! (Institutio III.2.3)
Things that are seen are temporal; things that are unseen are eternal.
We must observe that the knowledge of God which we are invited to cultivate is not that which, resting satisfied with empty speculation, only flutters in the brain, but a knowledge which will prove substantial and fruitful whenever it is duly perceived and rooted in the heart.