I’m thankful you’re concerned for your cousin, and I hope you’ll continue to pray for her and tell her about Jesus. The most loving thing we can ever do for anyone is to point them to Jesus Christ.
One approach might be to remind her that sincerity alone isn’t enough in life. Suppose, for example, you had a deadly virus, and after examining you the doctor said take any medicine you wanted—because as long as you were sincere, it would heal you. Would you follow his advice? I hope not, because sincerity alone wouldn’t be enough—and might even be dangerous.
The same is true with God. The Bible tells us that we all have a problem, and that problem is sin. Sin is like a deadly virus, invading our souls and corrupting our lives—and most of all, it cuts us off from God. Our greatest need is to be healed of our sins, for only then can we know God and be assured of eternal life.
But can we be healed of our sins? We can’t heal ourselves, no matter how hard we try or how sincere we are. Only God can heal us—and He made this possible by sending Jesus Christ into the world to die for us. Now by putting our faith and trust in Him we can be healed of our sins.
Encourage your cousin to face honestly her need for God’s forgiveness, and to give her life to Jesus. “He himself bore our sins in his body on the cross … ; by his wounds you have been healed” (1 Peter 2:24).