One of the most earnest prayers prayed in all of Scripture (not counting, of course, the prayer so earnest that Jesus's sweat turned to blood) is that prayed by Hannah at the yearly feast of worship at Shiloh. (You can find this prayer in 1 Samuel 1.)
Hannah was one of two wives of Elkanah, and she was the more loved of the two. But it was the other wife, Peninnah, who had been able to bear children and had thus given Elkanah all of his heirs, at least up to this point. As barrenness always has, this deeply troubled Hannah, who wanted nothing more than to bear a child for this man that she loved - and who loved her.
At the annual feast, Peninnah was mocking Hannah once more, making fun of her the way that she always had, the way that insecurities tend to make us do. She knew she was the lesser-loved wife, but at least she had given him children. The love he had for Hannah must have been pity-love. Yes, that must be it. What a waste of a woman, barren as she was, so Elkanah had no choice but to pretend to love her. Make no mistake - Hannah was a wife, but Peninnah was a mother, and she never let Hannah forget it.
So here is Hannah at the feast of great joy and worship, tears of absolute sadness streaming down her face. She was crushed...again...or maybe still. It was the one thing she wanted more than anything in the world, to have a child. It was the one thing it seemed she could not have. And every breath that Peninnah took only pushed Hannah's grief deeper into her very soul.
Thus, we find Hannah praying fervently before the Lord. From the depths of her very being, she pours out this prayer so earnest, so full of emotion, so full of her heart that the priest, Eli, mistakes her for being drunk. Her mouth is moving, but she speaks no words out loud. Her heart is stirring, but she makes no motion of it. She is just pouring herself out before God, a pure sacrifice at the yearly feast.
The exchange between Hannah and Eli is an interesting one, and it's worth engaging, though it is not particularly important to our discussion here. He accuses her of being drunk, telling her to go home and to never come before the Lord again in such an altered state. She explains that she is not in an altered state, but an altared one - her heart is deeply troubled, her soul crushed. Then, Eli blesses her and speaks over her a benediction, that the Lord would give her whatever it is that her heart has prayed for.
But what's beautiful is what happens next. Having finished her prayer and her conversation with the priest, Hannah rises to go on her way. And the Scriptures tell us, she wasn't sad any more (1 Samuel 1:18).
Don't read right past this. Pause here and think about what's happened. Think about what's going on.
Hannah's not pregnant. Nothing in her situation has changed. She is still a wife, and Peninnah is still a mother. No angel of the Lord has appeared to her, as had and will appear to so many other barren women, promising her a child. Her womb did not leap. We have no record of her "feeling" like things had changed or even believing that the next time she laid with her husband, she would conceive. Even the priest has not blessed her future child, but only acknowledged her prayer - non-specifically; he doesn't know what she has prayed for.
In other words, Hannah came to the Lord in deep sadness and walks away with no sadness and the only thing that has happened at this point is that she prayed.
Let that sink in. Hannah, deeply troubled, prayed, and she was no longer deeply troubled. Not because her circumstances had changed. Not because some promise had come. Not because an angel whispered in her ear. Simply because she prayed.
That right there is the power of prayer.