Emotions/feelings
Speaking of "tears", David cried many of them. He describes them in Psalms repeatedly. In one of the verses, in a prayer to God about his tears, he speaks of God, saving his tears in a bottle. Our tears are very precious to God. He promises that those who "sow in sorrow" shall "reap in joy", and that weeping may endure for a night but joy comes in the morning.
Emotions are from God. How can we not weep when we see the devastation of this fallen world and when evil is celebrated, etc.
Our tears amidst our prayers are precious to God because it is like "incense" rising up to God.
Psalms is very clear on what emotions are "of God" and which are not. Some emotions are downright sinful. Proverbs also exemplifies which emotions are evil because they originate from the enemy.
What comes to mind for me, in summary, is David dancing with all his might before the Lord. His "heart" was overflowing and thus dancing with joy before he even began physically dancing.
What is "joy"? It's an "emotion".
There is a REASON that God Himself called David the "apple of His eye", and a man "after His own heart".
This song comes to mind. When we love God and our hearts are overflowing with this love, thankfulness and praise, how can we keep from expressing it?
How can we keep from singing?