Take, for example, Elijah. James 5:17 says, “Elijah was a man with a nature like ours, and he prayed earnestly that it would not rain; and it did not rain on the land for three years and six months.” Elijah knew that his prayer would bring about unprecedented hardship upon the nation. But this was necessary because the king of Israel had led the people down a sinful path. In essence, Elijah wanted the nation to turn back to God and was prepared to pray to that end, even if it meant it would take three and a half years to be answered. Basically, Elijah was saying, “Whatever it takes, Lord, whatever it takes!”
Now God could say immediately after Elijah prayed that it was done — it was answered. But there was a season between when the prayer was prayed and the answer was manifested. You can pray for family members who are not believers, and God can say, “Done! I’ve heard your prayer, and the answer is on the way … but it’s going to take some time. I need to allow them to go through difficulties so their desire is turned from the world to Me.”
When you read about the whole event in 1 Kings 18, you know that Elijah’s prayer was answered immediately when he prayed it, but God had a special timing for Elijah to see his prayer completely fulfilled. Likewise, when you pray, it takes time, so don’t give up! Three and a half years of false comfort would have to be taken away from Israel and they needed to go through hard times to realize that they needed God.
Back to the demon-possessed son, when the disciples came to Jesus and asked, “Why could we not drive the demon out?” Jesus said to them that this kind of demonic possession only comes out with persistent prayer and fasting. In other words, “Don’t give up if you don’t see the answer immediately.” What God has promised, he will do!