It's an amazing thing to be able to move an audience with a carefully crafted song or melody, giving them a taste of your own emotions and experiences. To be able to do that effectively is a real gift, but a gift that needs to be developed.
Creating a unique song involves multiple steps—crafting lyrical ideas, expressing those lyrics through a memorable melody, working on the song harmonically and rhythmically, giving the song an appropriate structure, and honing all of those elements until it's perfect. Skill is required... and patience! Here is a range of tutorials from basic to advanced that explain it all.