Proverbs 28:9 He that turneth away his ear from hearing the law, even his prayer shall be abomination.
This verse tells us simply that if we do not follow the law of God, He will not here our prayers. God wants us to be obedient in all things and He does not want to here our prayers if we will not quit sinning. In Isaiah 1:15 it says “And when ye spread forth your hands, I will hide mine eyes from you: yea, when ye make many prayers, I will not hear: your hands are full of blood.” Then Isaiah 1:16 tells us what to do “Wash you, make you clean; put away the evil of your doings from before mine eyes; cease to do evil;” If we want God to here our prayers we need to listen to what this scripture says.