For as he thinks in his heart, so is he… Proverbs 23:7 (NKJV)
What you think about yourself matters. You can choose to focus on what you perceive to be your shortcomings. You have the option of focusing on the problems in your life. Or you can focus on what God thinks about you. You can spend your time focusing on your identity in Christ. You can focus on who God says you are. Spend some time today reminding yourself of who you are.
Read Ephesians 1 and 2. Make a list of who God says you are in Him. Post the list somewhere to remind yourself of your identity in Christ.