Whenever Wayne has performed - whether it be a major opera or singing a few songs for any size venue, he always starts by learning the story. He encourages his chorale to do the same. Actually he commands that we do so. Learn the story so you can speak it as confidently as if you had written it yourself. Practice saying the words as an actor or actress would deliver their lines. Then and only then can you start to learn the music. The music will come much faster if you aren't tripping over the words.
Tell the story and you will inspire your audience. Tell the story and you will engage their souls.