God is the Hearer and Answerer of prayer. Oftentimes, before the answer comes, something that is displeasing to Him must be taken away. Oftentimes, it is in relation to how we treat our fellow man. Prayer definitely has hindrances. Both sin and indolence will cause your prayers to not be heard. Just as the watchman keeps watch diligently, God is requiring you to be unceasing in the discharge of your duty to pray. His word to the Church is the same as Isaiah's word to Israel - "Give Him no rest." Intercede unceasingly for the establishment of His kingdom and Jesus' righteous rule on the earth.