Alas, the blue arc of heaven / Is covered with gloomy clouds, / And the bright radiance of the sun / Is completely hidden See the terrifying force of… - Caspar David Friedrich

Jesus Christ, nailed to the Cross [in his painting 'Cross in the Mountains (Tetschen Altar)',] is turned to the setting sun, here the image of the totally enlivening Father. With Christ dies the wisdom of the old world, the time when God the Father wandered directly on Earth. This sun set and the world was no longer able to apprehend the departed light. The evening glow shining from the pure noble metal of the golden crucified Christ is reflected in gentle glow to the earth. The Cross stands raised on a rock, unshakably firm, as our faith in Jesus Christ. Around the Cross stand the evergreens, enduring through all seasons, as does the belief of Man in Him, the crucified.

Through the gloomy clouds break / Blue sky, sunshine, / On the heights and in the valley / Sing the lark and the nightingale
God, I thank you that I live / Not forever in this world / Strengthen me that my soul rise / Upward toward your firmament.

If a painting has a soulful effect on the viewer, if it puts his mind into a soulful mood, then it has fulfilled the first requirement of a work of art. However bad it might be in drawing, color, handling, etc.