This artwork of the Communion of Saints (aka Church Triumphant) in Heaven is one of three parts of an altarpiece painted by Fra Angelico. The three rows of Saints are adoring the risen and glorified Christ, who is in the center altarpiece here. The left side of the altarpiece has the Virgin Mary, Apostles and other Saints here.
Click here to view the left altar piece.
Click here to view the center altar piece.