The sunday is sacred, cf. the fourth of the Ten Commandments
In Andersen's tales sundays rarely are sacred, except in a purely formal way. For Andersen himself the religious was very much a personal and inward affair, and he would rather perform his devotion uotside, in the nature, than in a church. One can get an impression of Andersen's thoughts about the church, God and nature in "A Story", part of the travelogue I Sverrig ('In Sweden'), 1851:
(...) there stood the corn, so beautifully green, while all the small birds chirped and twittered as happily as if they were having a great holiday.
And, indeed, people could rightly think of this as a holiday, for it was Sunday. The bells were chiming while people in their best clothes were walking to church and looking so cheerful. It was such a bright, warm day that one might well say: "How good God is to grant us so many blessings!"
But inside the church the preacher in the pulpit spoke in a loud and angry tone; he said that all humans were wicked and that God would certainly punish them by sending them to the eternal torments of hell when they died. He said that they would never find peace or rest in hell, for their consciences would never die nor would the fires ever be extinguished.
This was terrible to hear, but still he went on as if the subject he was explaining were really true. He described hell to them as a stagnant cave, where all the impure and sinful of the world would be; there would be no air, only the hot sulphur flames, and no bottom there, and the wicked would sink deeper and deeper into eternal silence forever!
It was horrible to hear this, but the preacher spoke from his heart, and all the people in the church were terrified.
But the birds outside the church sang joyously, and the sun was shining warmly; it was as if each little bird were saying, "Nothing is so great as the loving-kindness of the Almighty!"
Yes, outside the church, it was not at all like the preacher's sermon.
"We must have all the world spruced up by tomorrow morning," said Ole. "It's a holiday because it is Sunday. I must go to church steeples to see that the little church goblins are polishing the bells so that they will sound their best.