In 1810 he preached his famous probation sermon on the striking theme, "Why has the Word of God departed from His house?" The sermon produced a sensation, and from this time Grundtvig came to be known as a mystic and fanatic. His career as a pastor was checkered, but throughout his life he exerted a powerful influence by his literary activity as well as by his preaching. His poetry and hymns attracted so much attention that it was said that "Kingo's harp has been strung afresh." Grundtvig's strongest hymns are those that deal with the Church and the sacraments. The divine character of the Church is continually stressed, for Christ not only founded it, but, as the Living Word, He is present in it and in the sacraments unto the end of time. "Built on the Rock, the Church doth stand" is probably his most famous hymn. Grundtvig was more concerned about the thought he was trying to convey than the mode of expression; therefore his hymns are often characterized by strength rather than poetic beauty. They are also so deeply tinged by national spirit and feeling that they lose much of the color and fragrance of their native heath when translated. That Grundtvig could rise to lyrical heights is revealed especially in his festival hymns. There is a charming freshness in the sweet Christmas hymn: Chime, happy Christmas bells, once more! The heavenly Guest is at the door, The blessed words the shepherds thrill, The joyous tidings, "Peace, good will." O let us go with quiet mind, The gentle Babe with shepherds find, To gaze on Him who gladdens them, The loveliest flower of Jesse's stem. Come, Jesus, glorious heavenly Guest, Keep Thine own Christmas in our breast, Then David's harp-strings, hushed so long, Shall swell our jubilee of song. The Danish hymnologist Brandt has pointed out the distinctive characteristics of his country's three great hymnists by calling attention to their favorite symbols. That of Kingo was the sun, Brorson's the rose, and Grundtvig's the bird. Kingo extols Christ as the risen, victorious Saviour--the Sun that breaks through the dark shades of sin and death. Brorson glorifies Christ as the Friend of the spiritually poor and needy. They learn to know Him in the secret prayer chamber as the Rose that spreads its quiet fragrance. Grundtvig's hymns are primarily hymns of the Spirit. They laud the Holy Spirit, the Giver and Renewer of life, who bears us up on mighty wings toward the mansions of light. Among Danes and Norwegians there are few hymns more popular than Grundtvig's hymn on the Church. The first stanza reads: Built on the Rock the Church doth stand, Even when steeples are falling; Crumbled have spires in every land, Bells still are chiming and calling; Calling the young and old to rest, But above all the soul distressed, Longing for rest everlasting.