Source
Psalm 138
I will praise you with all my heart;
Before the gods I will sing.
2 I will bow down to your holy temple,
And I will praise your name for your mercy and your faithfulness;
Because you have magnified your name, and your word above all things.
3 The day that I called, you answered me;
You strengthened me with vigor in my soul.
4 All the kings of the earth will praise you, O Lord,
Because they have heard the sayings of your mouth.
5 And they shall sing of the ways of the Lord,
Because the glory of the Lord is great...
(RVR1960)
Praising God implies freedom in the whole expression of life, for this reason when we praise God we do it in front of everyone in front of unbelievers agnostic idolaters believing false gods ...
It is for all this that God wants us to seriously examine his word and give it all its value so that we can have conviction because we praise his glory and majesty.
God will fulfill and perfect his work in our life because the idea is that God begins his work in the life of the believer and continues it until it is absolutely and completely finished because he is faithful to his promise.
This idea of the psalmist that God will fulfill his promise and purposes in a person's life is also confirmed by the great men of God who made history in ancient times by the word of God.
God is completely faithful to his word, therefore he fulfills his promises in the men of the earth and specifically in all those who are faithful and keep his word in obedience and actions.
Furthermore, this psalm reminds us that God exalts the humble, hears him and helps him at all times but rejects the proud and looks at him from afar.