Elijah was a man with a nature like ours, and he prayed earnestly that it would not rain on the land for three years and six months.
And he prayed again, and the heaven gave rain, and the earth produced its fruit."
James 5:16-18 (NKJV)
There are certain jobs that only a few people are qualified for and able to do, for various reasons. For example, some people have gone through a certain type of training that has qualified and prepared them to do their job. It is not that the job itself is impossible for anyone else to do, it is just that some people were specifically trained for a specific job. But there are some jobs where the qualifications are not the same, and really anyone who is willing to work is qualified and can do that job.
Some Christians have the idea that only a few people can really pray and talk to God in a way that will get results. Sometimes people think that a pastor or someone else has been qualified to pray in a way that others are not. This is completely wrong. Even though some people may have learned how to pray according to biblical principles, and therefore they have more success with their prayers than others, each and every Christian is already qualified to pray.
In James, we are told that Elijah, the prophet who worked miracles, was a man just like us. Elijah was not some spiritual superman who was more qualified to pray than anyone else, Elijah got results in prayer because of Who he was praying to, not because he was some super saint. Through the new birth, because of the blood of Jesus, each and every Christian is in a relationship with God and is qualified to talk to God about whatever they need to and to have positive results. Who is qualified to pray effective prayers? Each and every Christian.