He was heard because he was righteous, because he prayed according to God's will, and because he used the persistence of true faith. Spiritual warfare involves testimony, prayer, praise, preaching, prophecy and proclamation. These are things we do with our words. We form weapons with our mouth. These words inspired by God become articles of war that defeat Satan and dislodge his influence.
High praises are especially powerful as tools of war.
Intercessory prayer, standing in the gap for others, is especially blessed of God. With words we bless men, exalt Christ, affirm our faith, and weaken and evict the demons. We cleanse our house with words. Words are weapons, especially when they are divinely inspired and prophetically timed. What I am seeing is that the intercessory prayer movement, one of the largest mobilizations of the Body of Christ in human history, will now move to a new level of maturity.