The whole point of Faith is believing.. You can not Doubt GOD, Nor his power and existence. Even in your thoughts he can hear. I used to be the same id try very hard to find GOD or feel something.. and i couldnt so i got frustrated and started cursing and saying there is no GOD over and over again with rage. But everytime after saying this i would start praying and saying sorry because i knew it was the right thing to do. I couldnt not pray. I do it everyday/night..
and those evil thoughts in your head.. They devleoped from your past. If u have done something really horrible to others or something really horrible happend to you from other individuals.. Thats where they come from your past and how u were raised with friends and even family.. Hate - regret - disapointment - Constant rage - revenge.. You just cant stand what happend in the past.. Repent.. I did i was all of the above the constant really evil thoughts and loudness in my mind. ever since i repented my mind has never been more quiet and the past for me has slowly drifted away.. Like ive been forgiven.. and when i say repent U have to do it with your heart.. I prayed for repentance.. and i got it.. You keep praying for it and u will get it too. God will lift the burden of your sins.. Then you can truly be free. GOD will always answer a heart felt prayer. 100% true. Keep trying you will get there.. Believe and stay strong.

GOD BLESS <3

Good advice. Blessings