what is your opinion on extraterrestial life and ufo visitations ?

I strongly believe that there are other entities sharing this world with us and they have been for a lot longer than we think. Their purpose, to heal the planet and to bring everyone together in one state of mind and peace. However the opposite idea of them wanting to destroy the planet or take over may seem more exciting, but in reality, if they are as far advanced in their knowledge and being as told, then why havent they just destroyed us before now ? ooooh i love a good debate x