"For as he thinketh in his heart, so is he" Pr 23:7.
We must never underestimate the power of our thoughts. Those unspoken dialogues we have with ourselves are very influential.
So often we are held captive to negative, derogatory thoughts about ourselves or even about others. We forget all about the truth and end up believing lies. We forget how fearfully and wonderfully we are made (Ps 139:14), and how amazing our lives in Christ really are! We doubt our abilities, even though the Sovereign Lord of all the universe has entrusted us with our tasks.
Take every thought captive into obedience (2 Cor 10:5) is not just referring to sinful thoughts, but the thoughts that have us operating out of anything but the truth. The truth is that we are created in His image (Gen 1:27), we are more than conquerors (Rom 8:37), we are deeply loved (Jer 31:3), we are able to do all things through Christ, because He strengthens us (Phil 4:13).
Correct your thinking, cast out the falsehoods, and walk in truth. The day will be magnificent, and amazing, full of God's blessing because "we know that all things work together for good to them that love God, to them who are the called according to his purpose." Rom 8:28.