After Thought:
While reading Psalm 13, I thought to myself...could the reference to God in pronouns "Thou" and "He" in the same passage be hinting to the Holy Trinity? (Thou = 2nd person; He = 1st person).
Because "my heart shall rejoice in THY salvation" v. 5. "rejoice in THY salvation" 9:14.
Of course, the rule of this is not consistent throughout the Psalms. That "you" does not always refer to Christ while/if "he" refers to the first person.
Update 3/11/2023:
Recalling Paul Murphy's take on this during Thursday Bible Study long time ago, of MERF in Time Square New York. He called this one of the most depressing Psalm, as if the psalmist has lost hope. His point, perhaps, was to describe the depth of a Christian's suffering. But Murphy never gave a clear ending, as if this is just how it is. I've always wondered why he purposely missed the last two verses: Psalms 13:5,6. Because that's the key to the whole psalm and completely opposite of what Murphy was leading. Murphy was not the only one, Michael Keller also alluded to similar faulty exegesis. So I don't know from which America genius theologians (if any) they got this from.
So what is this about? It certainly rebut the other extremes: That those who never experience pain and suffering yet thinking themselves in piety would assume that there's no pain in this world could cause them to mourn to God. As some fundamentalists kind I've seen in even my current church. These would never go to New York City, they would stay out of it. They would think that no one is ever called for complications in life, and they believe those who do are foolish.
This passage rhymes with Tong's take on James 5:13. Pray in secret when afflicted; Rejoice in public when merry. Contrary to the world's announce in public when afflicted; Seek after self fulfilment. Such is also the lesson from Romans 5:3-5. Overall, we do rejoice in our sufferings. There is good reason for such joy, as David did: "I shall rejoice in thy salvation".
This is not just about trusting God or the fact that God wins. This is about one's relationship with God. How one should want to see clearly and truly rejoice in spite of opposite circumstances one MUST face. Emphasis on MUST. And because of this "MUST", being confronted rightly, would only cause the saints to mourn. The same way Christ exclaimed in Matthew 23:37:
O Jerusalem, Jerusalem, the city that kills the prophets and stones those who are sent to it! How often would I have gathered your children together as a hen gathers her brood under her wings, and you were not willing!
Therefore, if one just simply says: Trust God, God wins, there should be no pain felt, no meaning in suffering, one cannot truly fathom what Christ meant without going off-rail in hermeneutics. On the other hand, in the same way, should this be treated a depressing thing, one accuses God of being so just that He is unjust.
This even the secular understood: An Unexamined Life is Not Worth Living. Suffering is not welcomed but it is a must, for learning, for spiritual growth, for sanctification, for battling the wicked. One extreme considers suffering not welcomed nor a Must; the other extreme considers suffering welcomed (irrelevant for God wins) but not a must (run away from it by calling it foolish). Of course, the flagellants in their ascetic practices view suffering welcoming and a must, but this error is of old, not worth mentioning here. This is the context to understand "Rejoicing in our suffering".
v.5-6: This psalm is a reminiscence of Job. A better response for Job is given in verses 5-6. Especially in verse 6, indication the chief end of man, which Job did not in his agony relate.