Most of the Old Testament (and the New) is written in the form of advocacy. The authors were advocating primarily to fellow Israelites about the character of God. Even the first books of the Bible are written in this respect. God is the God who creates the universe, leads Israel out of Egypt, and delivers them into the promise land. This testimony (the first books of the Bible) was written to create a picture of Israel’s God, to give God a written history, helping distinguish Him from the idols and gods of the pagans.

The writers of the Bible were not writing sermons to docile students or accepting churchgoers. The writers were competing with real threats to God, threats in the form of wrong speech or abandonment for other gods. It would be a fatal conceit to ignore, downplay, or allegorize their speech. Their speech was meant to define God.

Because the text mostly comes in the form of advocacy, most of the text explicitly puts God on trial before Israel. God continually strives for dominance in Israel’s hearts and minds against the gods of the pagans. God demeans the pagan gods. God reminds Israel of His powerful works and faithfulness. God appeals to future blessings if Israel returns. God is concerned with correct and faithful worship of Himself. As such, the authors are keen to distinguish between correct speech about God, and incorrect speech.

One such explicit trial of God is found in Psalms 115:

Psa 115:1 Not unto us, O LORD, not unto us, But to Your name give glory, Because of Your mercy, Because of Your truth.

The first verse contrasts God and men. God should be given glory, not men. This glory is not given arbitrarily, but because God shows “mercy” and because God is faithful (“true”). If God ceased to be those things, God would lose the right to be given glory. The next verses claim as much:

Psa 115:2 Why should the Gentiles say, “So where is their God?”
Psa 115:3 But our God is in heaven; He does whatever He pleases.

The author begins a contrast with the Gentile gods. The Gentile claim was that Yahweh could not be seen or was not effective. The Gentile claim was that Yahweh had abandoned Israel. The author disagrees. God may not be seen, but God is in heaven and does whatever He wants. The author’s claim is that not only has God not abandoned Israel, but God is powerful and active. The author then turns the pagan claim on its head, and mocks the gentile gods. Sure, their gods can be seen, but that is about the extent of it:

Psa 115:4 Their idols are silver and gold, The work of men’s hands.
Psa 115:5 They have mouths, but they do not speak; Eyes they have, but they do not see;
Psa 115:6 They have ears, but they do not hear; Noses they have, but they do not smell;
Psa 115:7 They have hands, but they do not handle; Feet they have, but they do not walk; Nor do they mutter through their throat.

In this text, the author is contrasting the living God with the dead gods of the idols. To this author: speaking, hearing, smelling, handling, walking, were all dynamic traits that distinguished Yahweh as superior to the idols. If the author believed that Yahweh did not encompass these traits, the criticism falls flat. This imagery of Yahweh being living and dynamic is a consistent theme throughout Scripture.

Psa 115:8 Those who make them are like them; So is everyone who trusts in them.

Because people were worshiping these impotent statues, they themselves were impotent. By worshiping a fake god, there was no real god defending the pagan’s claims. Implicitly this is contrasted to the God of Israel: Yahweh is the God who is powerful, thus anyone who puts their faith in Yahweh will likewise be powerful.

The author goes on to say just this:

Psa 115:9 O Israel, trust in the LORD; He is their help and their shield.
Psa 115:10 O house of Aaron, trust in the LORD; He is their help and their shield.
Psa 115:11 You who fear the LORD, trust in the LORD; He is their help and their shield.
Psa 115:12 The LORD has been mindful of us; He will bless us; He will bless the house of Israel; He will bless the house of Aaron.
Psa 115:13 He will bless those who fear the LORD, Both small and great.
Psa 115:14 May the LORD give you increase more and more, You and your children.

The author had begun the chapter by comparing the living God to the dead gods of the pagans. He then implores Israel to trust in God (as opposed to the dead gods). The author is advocating for a correct understanding of the true God. In what seemed like an advocacy against Gentiles was really an advocacy against Israelites who had adopted the Gentile gods. The Gentiles were converting Israel away from Yahweh. This entire chapter is a response to this.

By believing in God, only then will God bless Israel. God is powerful. God is the God who helps. God is the God who blesses. God is the God who prospers. Israel’s is being promised blessings in return for their faith in Yahweh. The author again appeals to God’s power:

Psa 115:15 May you be blessed by the LORD, Who made heaven and earth.
Psa 115:16 The heaven, even the heavens, are the LORD’s; But the earth He has given to the children of men.

God had created the heaven and earth, by extension: “the universe”. This speaks to God’s power. To the author, it was important that Israel knew that their God, not the idols of the Gentiles, created the world. Not only did God create the Earth, God created a holy place for Himself in heaven. This is where, earlier in the book, God is said to be (“our God is in heaven”). But speaking to God’s generosity: although God also created the world, He gave it to men. God does not horde power for Himself. God instead gives lavish gifts to men.

Psa 115:17 The dead do not praise the LORD, Nor any who go down into silence.
Psa 115:18 But we will bless the LORD From this time forth and forevermore. Praise the LORD!

This last section contrasts the dead (who do not worship) with Israel, who should worship God. The point seems to be that people should worship God now because after they die there will be no opportunity for worship (whatever that may entail in the author’s view of the afterlife).