Isaiah 41:10

Don't you be afraid, for I am with you. Don't be dismayed, for I am your God. I will strengthen you. Yes, I will help you. Yes, I will uphold you with the right hand of my righteousness.

WEB

Fear thou not; for I am with thee: be not dismayed; for I am thy God: I will strengthen thee; yea, I will help thee; yea, I will uphold thee with the right hand of my righteousness.

KJV

What Isaiah 41:10 means

It means God tells his people not to be afraid, because he is with them, he is their God, and he will strengthen and uphold them.

Spoken to Israel in fear, the verse answers anxiety with God's presence rather than with a change in circumstances. The reasons it gives are all about who God is: with them, their God, strengthening, helping, holding. It is one of Scripture's clearest words for the frightened.