Elijah prayed seven times for something that was good, something that was promised: the rain necessary to end a famine of three-and-a-half years. It took more than one prayer. Sometimes we must persevere in prayer.
God certainly hears us the first time we pray, if our prayer comes from a forgiving, humble heart of service to Him (see Sir 35:16-17). Elijah did not grow skeptical the first time he prayed for rain and no rain came. He believed God and trusted Him, and prayed yet again, seven times (1 Kgs 18:41ff). "The fervent petition of a holy man is powerful indeed. Elijah was only a man like us, yet he prayed earnestly that it would not rain and no rain fell on the land for three years and six months. When he prayed again, the sky burst forth with rain and the land produced its crop" (Jas 5:16-18).
The need for persistence in prayer is for our good. It teaches us to go to God spontaneously and regularly. We learn that God is the Source of all. It teaches us to not turn our backs on God and reminds us to be grateful to God upon receiving the answer to our prayer. Though God never sleeps nor slumbers (Ps 121:4), it can seem to us that He does not hear us when our prayers are not answered quickly. We thus need to pray persistently not so He can hear us better, but so that we can learn to hear Him better.
Perseverance in prayer trains us in the discipline of the Lord. Jesus put His hands on the blind man twice to heal him (Mk 8:23-25). So pray with persistence and perseverance. Would we have a culture of death if enough believers had persevered in praying decades ago? Persevere in prayer today for the Church of the future.