"...it is in Genesis there is your Proof they have visited before and will again.."
Genesis is proof of nothing. It's a book. It's words printed on a piece of paper. I read Jurassic Park. It isn't proof we've cloned dinosaurs. And please don't start with that circular reasoning. "How do you know it's true?" "Because it's in the Bible!" "How do you know the Bible is true?" "Because it's the word if God!" "How do you know it's the word of God?" "Because it says so in the Bible!"
Sorry, but the angel thing isn't working for me either. And I'll believe in aliens from Alpha Centauri before I buy that!
"From our orbital vantage point, we observe an earth without borders, full of peace, beauty and magnificence, and we pray that humanity as a whole can imagine a borderless world as we see it, and strive to live as one in peace." Astronaut William C. McCool RIP, January 29, 2003 - Space Shuttle Columbia