A. W. Tozer told this story from his youth: "I’ve often wondered how a hen must feel about sitting for three weeks on an egg. My mother always put thirteen eggs under a hen and the old girl would sit right there. She might take a little coffee break once in awhile, but back she’d come again to the nest. For the first week, it was a novelty. Two weeks of it she might endure, but that last week must have been torture—just sitting there with nothing happening.
"Then about noon of the twenty-first day, the first little experimental peep is heard under her wings. And she smiles as only a hen can smile and says, ‘Thank God, they’re here.’ After that it is just a question of time. One after the other, the chicks peck themselves out of their shells. I used to get down on my hands and knees as a boy and watch them pecking themselves out. They’re messy when they first appear, but give them about ten minutes in the sunshine and they’re as fluffy as can be, and lovely to look at. But they only come after twenty-one long days of waiting.
"God sometimes makes us wait. He made the disciples wait in Jerusalem for the Holy Spirit (Acts 1:4) and He may make you wait. But remember, God is faithful who called you, and He also will do it [1Thessalonians 5:24]."