I will love thee, O Lord, my strength. The Lord is my rock, and my fortress, and my deliverer; my God, my strength, in whom I will trust; my buckler, and the horn of my salvation, and my high tower. I will call upon the Lord, who is worthy to be praised: so shall I be saved from mine enemies.
-Psalm 18:1-3
I love these words: strength, rock, fortress, deliverer, my buckler, the horn of my salvation, my high tower. And then, what does he say? I will call upon the Lord, and so I shall be saved. God has unfathomable power, but we have to call upon Him. He won't save me unless I ask.
Then David writes:
In my distress I called upon the Lord, and cried unto my God: he heard my voice out of his temple, and my cry came before him, even into his ears.
-Psalm 18:6
In my distress, I too have called upon the Lord, and He has heard me. When I have been crushed by dark despair, He has lifted me and lightened my way. When I could see no way out of my trials, He walked with me. When I have felt alone, He has come to my side. But only when I asked.
In his Psalm David describes all the ways God has intervened for him with great displays of heavenly power, and then he concludes:
With the merciful thou wilt shew thyself merciful; with an upright man thou wilt shew thyself upright; With the pure thou wilt shew thyself pure. . . For thou wilt save the afflicted people. . . For thou wilt light my candle: the Lord my God will enlighten my darkness.
-Psalm 18:25-28
God will be merciful to me and to all those who call upon Him. We just need to ask. A simple, sincere prayer. All that power is waiting to protect us and save us. Smoke, fire, hot coals like hail, hurricanes, thunder, brilliant light - it is all available, God's full power and glory - when we ask.
David ends his Psalm with these words of praise and gratitude:
Therefore will I give thanks unto thee, O Lord, among the heathen, and sing praises unto thy name. Great deliverance giveth he to his king; and sheweth mercy to his anointed, to David, and to his seed for evermore.
-Psalm 18:49-50
God has shown mercy to me, David, though I am not a king. May He show great mercy to my children and all that come after me.