"Now Thomas (called Didymus), one of the Twelve, was not with the disciples when Jesus came. So the other disciples told him, 'We have seen the Lord!' But he said to them, 'Unless I see the nail marks in his hands and put my finger where the nails were, and put my hand into his side, I will not believe it.' A week later his disciples were in the house again, and Thomas was with them. Though the doors were locked, Jesus came and stood among them and said, 'Peace be with you!' Then he said to Thomas, 'Put your finger here; see my hands. Reach out your hand put it into my side. Stop doubting and believe.' Thomas said to him, 'My Lord and my God!' Then Jesus told him, 'Because you have seen me, you have believed; blessed are those who have not seen and yet have believed.'" (John 20:24-29, NIV)
It's easy to let doubt creep into our minds. And the enemy loves to use that against us time and time again. He likes to cause us to doubt our faith, our trust in God, and what God has told us in His Word. Doubt is used as a weapon against us. So, if we know that it's used as a weapon, we should be ever more alert to be aware of it. Ask yourself when you start to doubt something out of the blue that you would not normally doubt.
Those of us who have struggled with depression and mental disorders can find it easy to think we will never get better or get our illness under control, even though we are following doctor's orders and being responsible with our care. We've seen the worse of ourselves in things that are in chaos mentally. And we don't want to see it again. But we have a God who sees all, knows all and knows you! He wants to see you set free and live free:
"'For I know the plans I have for you,' declares the Lord, 'plans to prosper you and not to harm you, plans to give you hope and a future.'" (Jeremiah 29:11 NIV)