This is a question from a twenty-year-old boy. I have a problem that there are often bad thoughts in my mind—thoughts which compel me to commit sins which I cannot explain. I am very much concerned about resolving this problem. Please tell me how I should change my mindset.
Your concerns about your moral being and cleansing your mind of bad thoughts are commendable. I would suggest a three-fold strategy for the purpose.
What you want to do depends upon your inner strength. You need to nourish your will power, which you can employ to achieve whatever noble task you want to accomplish. Being a Muslim, you should know that the purpose of your creation is nothing but submission to God. Committing sins amounts to denying this submission. This is what will deprive a person of the immense reward which Allah has prepared for the purified souls. Our ultimate destination and eternal abode is Jannah (Paradise). You should explain to yourself that you have a great goal before you. And those who strive for nobler ideals overcome each and every obstacle that comes their way: be great as your goal is great.
You need to convince yourself that you are a strong boy and not someone who is as fragile as to give in to trying circumstances in no time. Strong people fight till they achieve what they strive for or they give their life for their objectives.
You also need to explain to yourself that your Creator knows what you do; He also knows what notions are whispered into your heart by Satan. He will obviously not hold you accountable for what you are not responsible in your capacity as individual. We however must always bear in mind that we are not allowed to dwell on and entertain these thoughts. We do not commit sins in public because we know people are watching us and they may thus rebuke us. We need to remember that the Lord is always with us; we should therefore refrain from whatever is low; we should be fearful of Him in order to avoid risking His wrath.
You should introspect and determine the reason why you resort to sins. For pleasure? Nay! You should tell yourself that worldly pleasures are transitory in nature as the world itself is. It is only prudent to renounce what is transitory and illegitimate for that is what is permanent and sublime.