Psalms 146:6

Which made heaven and earth ... - Who is the true God, the Creator of all things. Happy is he who can address the God who called all this wondrous universe into being, and who sustains all by his power, as his God.

Which keepeth truth for ever - Who is always true to his promises. In this verse there are two reasons given why the lot of the people of God would be a happy one:

(1) That Yahweh is the true God, the Creator of all things, and, therefore, able to protect and provide for them.

(2) That he is faithful, and may always be relied on.

Idol-gods have no power, and every reliance placed on them is a vain reliance; people are often false and cannot be trusted, but Yahweh has infinite power, and every promise that he makes will be fulfilled; all that he says is eternally and unchangeably true. The reasons for trusting in him, or the reasons why they who trust in him are “happy,” are further stated in the following verses.