John Calvin Commentary Matthew 5:8

"Blessed are the pure in heart: for they shall see God." — Matthew 5:8 (ASV)

Happy are they who are of a pure heart. We might be inclined to think that what Christ states here aligns with everyone's judgment. Purity of heart is universally acknowledged to be the mother of all virtues.

And yet, there is hardly one person in a hundred who does not elevate craftiness to the position of the greatest virtue. For this reason, those people are commonly considered happy, whose cleverness is employed in the successful practice of deceit, who skillfully gain advantages by indirect methods over those with whom they interact.

Christ does not agree at all with worldly reasoning when He pronounces those to be happy, who take no pleasure in cunning, but interact sincerely with people, and express nothing, by word or appearance, that they do not feel in their heart.

Simple people are ridiculed for their lack of caution and for not looking out for themselves sharply enough. But Christ directs them to higher perspectives and urges them to consider that, if they do not have the shrewdness to deceive in this world, they will enjoy the sight of God in heaven.