Sing praises to the LORD, O you his saints, and give thanks to his holy name. For his anger is but for a moment, and his favor is for a lifetime. Weeping may tarry for the night, but joy comes with the morning.
Praise is offered to God for the balance that He brings in our lives. Yes, we may displease Him in our sin, but He is quick to forgive and be merciful to the repentant heart. And even when sin is judged, it is tempered with a lifetime of God's grace upon the repentant. God is merciful and loving and we praise Him for being such to us at all times.
Praise puts perspective on our sufferings. Trials do come. We hurt. We grieve. We suffer in the world by the actions of ourselves, of other sinners, and from the sheer mortality of the curse upon sin. Yet even in our suffering God can bring joy. Such joy is not earthbound. It is transcendent and heavenly. It defies emotional logic because God brings joy in our suffering.
God is a God Who knows suffering. Our sins have hurt and angered Him. He sent His Son to die for our sins. Jesus suffered more than we will ever come close to understanding when upon the cross He was forsaken by the Father. And in that suffering as the Man of Sorrows He bore our griefs. And that is why joy will come in the morning. Jesus knows our sufferings and will bring us joy if we can just trust Him for the relief of His presence that comes with the dawn.