God’s love is the source of their calling. The Father has sovereignly chosen to set his love upon the people addressed here and make them part of his people (similar to God’s decision to call Abraham and Israel as in Deuteronomy 4:37; Deuteronomy 10:15, Psalm 78:68).
1 Jude, a servant of Jesus Christ and brother of James, To those who are called, beloved in God the Father and kept for Jesus Christ: