And to know the love of Christ, which passeth knowledge.
—Ephesians 3:19

The knowledge of Christ, and of his love, is deservedly, in this place, set down among the desiderata Christianorum, the most desirable enjoyments of believers in this world. This love of Christ had entered the apostle’s heart; he was swallowed up in the meditation and admiration of it, and would have all hearts inflamed and affected with it, as his was.

Some think the apostle speaks extatically in this place, and knows not how to make the parts of his discourse consistent with each other, when he puts them upon endeavours to know that love of Christ, which himself confesses to pass knowledge.

But though his heart was ravished with the love of Christ, yet there is no contradiction or inconsistency in his discourse. He doth earnestly desire for the Ephesians, that they may know the love of Christ; i.e. that they may experimentally know his love, which passeth knowledge: That is, as some expound it, all other kinds of knowledge; yea, and all knowledge of Christ, which is not practical and experimental. Or thus: Labour to get the clearest and fullest apprehensive knowledge of Christ and his love, that is attainable in this world, though you cannot arrive to a perfect comprehensive knowledge of either.

—John Flavel
Works, 6:456.