A selection of verses showing that God is all-powerful and never changes.
King David tells the Israelites of God's greatness:
10 Therefore David blessed the LORD before all the assembly; and David said, “You are blessed, LORD, the God of Israel our father, forever and ever. 11 Yours, LORD, is the greatness, the power, the glory, the victory, and the majesty! For all that is in the heavens and in the earth is yours. Yours is the kingdom, LORD, and you are exalted as head above all.
The psalmist makes it clear that God has great power:
4 He counts the number of the stars.
He calls them all by their names.
5 Great is our Lord, and mighty in power.
His understanding is infinite.
6 The LORD upholds the humble.
He brings the wicked down to the ground.
7 Sing to the LORD with thanksgiving.
Sing praises on the harp to our God,
8 who covers the sky with clouds,
who prepares rain for the earth,
who makes grass grow on the mountains.
The prophet Jeremiah echoes the same thoughts:
15 “He has made the earth by his power.
He has established the world by his wisdom.
By his understanding he has stretched out the heavens.
16 When he utters his voice,
there is a roar of waters in the heavens,
and he causes the vapours to ascend from the ends of the earth.
He makes lightning for the rain,
and brings the wind out of his treasuries.
God uses his power to bring about our salvation:
3 seeing that his divine power has granted to us all things that pertain to life and godliness, through the knowledge of him who called us by his own glory and virtue, 4 by which he has granted to us his precious and exceedingly great promises; that through these you may become partakers of the divine nature, having escaped from the corruption that is in the world by lust.
The apostle James reminds us that God doesn't change:
17 Every good gift and every perfect gift is from above, coming down from the Father of lights, with whom can be no variation, nor turning shadow.