I’m thankful for your cousin—and you should be also, because he honestly cares about you, and he knows you are headed down a dead-end road. He knows the truth of Jesus’ warning: “Wide is the gate and broad is the road that leads to destruction, and many enter through it” (Matthew 7:13).
The first thing I’d say is that I feel very sorry for you, because you aren’t only turning your back on God, but you’re turning your back on His perfect plan for your life. God loves you, and He wants to give you true joy and peace and purpose—but so far, you’re missing them. Jesus said, “The thief [Satan] comes only to steal and kill and destroy; I have come that they may have life, and have it to the full” (John 10:10).
But I also would give you a word of warning. You may not see any reason to bother with God—but what of the future? Where will you turn when the doctor says it’s cancer, or someone you love turns against you, or you face any other problem you can’t control? Most of all, how will you face death and eternity without God? The Bible warns, “People are destined to die once, and after that to face judgment” (Hebrews 9:27).
Don’t let pride, or your slavery to some particular sin, or anything else keep you from Jesus Christ. He loves you so much that He gave His life for your salvation. Don’t ignore Him any longer, but by faith give your life to Him.