Thinking is a constant part of life. Thousand of thoughts fly through our head everyday and all day. But what are our thoughts about? Are they hateful thoughts when we're angry with our siblings, disrespectful thoughts about our parents, thoughts of complaint when things don't go our way? Or, are they the type of thoughts that Philipians 4:8 says we should have? "whatever things are true, whatever things are noble, whatever things are just, whatever things are pure, whatever things are lovely, whatever things are of good report, if there is an virtue and if there is anything praisworthy-meditate on these things."
The angry and bitter thoughts are the kind of thoughts we should really watch out for because they can easily creep their way into our minds, and once they're there it can be very hard to overcome them. Colossians 3:2 says "Keep your mind on the things of above, not on things on the earth." It's when we're focusing on ourselves and our worldly desires and worries that we have the angry and bitter thoughts which lead to an angry and bitter attitude.
Our thoughts aren't something that is only known by us and who we tell our thoughts to, God knows all of our thoughts and He's going to judge every one of them. Our thoughts can be pleasing to Him or they can dissappoint Him and make Him angry.
A few things we can do to help get our thoughts off ourselves and onto to "praise-worthy things" is to spend time reading and studying God's Word. Psalms 119:97 says "Oh, how I love your law! It is in my meditation all the day." To learn about His law we have study His word, And we can pray. Spend time with God in prayer, praise Him and give thanks to Him. John 16:24 says "Until now you have asked for nothing in My name. Ask and you will recieve, that your joy may be full." So we can ask Him for help and He will give it to us.