For Jesus’ calling of his disciples see Matthew 4:18-22, Mark 1:16-20, Luke 5:1-11, and John 1:40-42.
For his general call to all disciples see such passages as Matthew 16:24-28, Luke 9:23-27, 14:25-35; and 17:22-37.
Stanza 2 warns us against “the vain world’s golden store” and “each idol,” a parallel warning to that of the Decalogue given on Mt. Sinai. Similarly, Heidelberg Catechism, Lord’s Day 34, Question and Answer 95 says: “Idolatry is having or inventing something in which one trusts in place of or alongside of the only true God, who has revealed himself in the Word.”