8 We do not think it necessary to set forth here the praises of such instruction or to point out how meritorious it is in God's sight. If, assuredly, the alms with which we relieve the needs of the poor are highly praised by the Lord, how much more precious in His eyes, then, will be the zeal and labor expended in teaching and admonishing, by which we provide not for the passing needs of the body but for the eternal profit of the soul! Nothing, surely, is more desirable, nothing more acceptable to Jesus Christ, the Savior of souls, Who testifies of Himself through Isaias: "To bring good news to the poor he has sent me."
Source: Acerbo Nimis (Vatican.va)