If we find that we struggle with a low self-image, we need to look carefully at it, because it may not be low at all. It may in fact be a frustrated inflated self-image. Paul wrote this in Romans 12:3:
For by the grace given to me I say to everyone among you not to think of himself more highly than he ought to think, but to think with sober judgment, each according to the measure of faith that God has assigned.
What our world often calls low self-image, I think Paul would say is just another way of thinking too highly of ourselves.
Holy and Unholy Ways of Thinking Highly of Yourself
There’s a holy and humble way to think highly of yourself. If you are a Christian, you are a saint who is part of "a chosen race, a royal priesthood, a holy nation, a people for [God's] own possession that you may proclaim the excellencies of him who called you out of darkness into his marvelous light" (1 Peter 2:9). You are a new creation in Christ and no longer that old condemned person (2 Corinthians 5:17). God intends for this to be part of your self-image.