249 To safeguard man's dignity as a creature of God endowed with a soul in the image and likeness of God, the Church has always demanded a diligent observance of the third Commandment: "Remember that thou keep holy the sabbath day." (52) God certainly has the right and power to command man to devote one day a week to his duty of worshipping the eternal Majesty. Free from mundane cares, he should lift up his mind to the things of heaven, and look into the depths of his conscience, to see how he stands with God in respect of those necessary and inviolable relationships which must exist between the creature and his Creator.
Source: Mater et Magistra (Vatican.va)