I've realized the idea that you can lose your salvation comes from pride and lack of understanding of God's love. It implies "Yes, God loves you, but He already went through enough trouble for you, so you had better buckle down and make sure you don't screw up." Furthermore, it argues I must do something to keep my salvation. But the reason I have faith is because God gave it to me. The reason I repented and have any desire at all for God is because He gave it to me. Therefore how could I, a new creation, be an old creation ever again?
Our Fathers Word clearly says at the beginning of Jude "To those who are called, beloved in God the Father and kept by Jesus" Beloved. Imagine if you're crossing the road with your child. Are you at all going to loosen your grip on your son or daughter even though he or she may want to break away and run for it? Would you rely on your child's grip on you or your grip on your child?
How do these people sleep at night who do not believe in eternal salvation? You have the potential to spend eternity in hell. (or so you think) Or do you flatter yourself with how faithful to God you think you are?
God says He is the perfect Father. What perfect Father doesn't protect His child? And if God is the Almighty, and He is. So who then can separate us from the love of God in Christ? You're kept by God and God alone. What is the point of grace if you can lose it?
There are plenty of other places where the Holy Spirit talks of God's protection for us.