The Bible is full of accounts of people whose fervent prayers were answered. For example, Hannah was unable to have a child, but the Lord answered her prayer, and she gave birth to a little boy, Samuel, who became a great prophet (1 Samuel 1:9–20).
Paul and Silas were in prison for preaching the gospel. But instead of complaining, they sang praises unto God. Their entire situation was turned around by prayer, and they were freed from prison (see Acts 16:22–35).
Peter was also in prison for preaching the gospel, so the church got together and prayed. And within hours, their prayer was answered and Peter was released (see Acts 12:5–10).
The prophet Elijah prayed and the rain stopped. Later he prayed again, and the rain started up once more. He was a man who prayed, and God answered his prayers (see 1 Kings 17, 18).
We hear stories like this, and we might say, "But these were great people of faith. I am just an ordinary person. Certainly God would not hear my prayers in the same way." But that is not true. Elijah was a man with a nature just like ours (James 5:17). He was an ordinary man, made of flesh and blood.
One thing that clearly stands out in the Bible is that prayer can dramatically change things. And more importantly, prayer can change you.