John Wesley on James 1:25

But he that looketh diligently - Not with a transient glance, but bending down, fixing his eyes, and searching all to the bottom. Into the perfect law - Of love as established by faith. St. James here guards us against misunderstanding what St. Paul says concerning the "yoke and bondage of the law." He who keeps the law of love is free, John 8:31, &c. He that does not, is not free, but a slave to sin, and a criminal before God, James 2:10. And continueth therein - Not like him who forgot it, and went away. This man - There is a peculiar force in the repetition of the word. Shall be happy - Not barely in hearing, but doing the will of God.