Selection from Arcana Cœlestia ~ Emanuel Swedenborg
"to serve the Lord" denotes to perform uses, is because true worship consists in the performance of uses, thus in the exercises of charity. He who believes that serving the Lord consists solely in frequenting a place of worship, in hearing preaching there, and in praying, and that this is sufficient, is much mistaken.The very worship of the Lord consists in performing uses; and during man's life in the world uses consist in everyone's discharging aright his duty in his station, thus from the heart being of service to his country, to societies, and to the neighbor, in dealing sincerely with his fellow, and in performing kind offices with prudence in accordance with each person's character. These uses are chiefly the works of charity, and are those whereby the Lord is chiefly worshiped.
Frequenting a place of worship, hearing sermons, and saying prayers, are also necessary; but without the above uses they avail nothing, because they are not of the life, but teach what the life must be. The angels in heaven have all happiness from uses, and according to uses, so that to them uses are heaven.
(from Arcana Cœlestia 7038)