I believe in extraterrestrial life being out there....somewhere. I think there are species much more advanced than we are that have had successful civilizations longer than we've walked upright and worn clothing. But I don't have any
concrete evidence to prove any of that and I don't walk around ever pretending that I do. Belief in something that might be very distinctly possible is one thing, but saying that you can prove it and everybody who disagrees is some fool or idiot who has been brainwashed into going to sleep is another.
There is no face on Mars. The Cydonia mound was a trick of lights and shadow at the time of the 1976 Viking 2 mission to the planet. It was essentially one enormous Rorschach test that allowed a lot of people to see a humanoid face with eyes, nostrils and a slit-shaped mouth. I'll admit, it looked a hell of a lot like a humanoid face with a hairline.
But it's not. It's just a natural rock formation of some sort that's the result of eons of wind and possibly ancient water erosion. The Cydonia region is no more or no less interesting nor peculiar than any other part of the current Martian landscape unless the "Face" believers want to make it a bigger deal.
If somebody wants to prove the existence of alien civilizations and life, these kind of discredited conspiracy theories being pushed by guys like Dr. Richard Hoagland are not the way to go. The truth is probably going to be a helluva lot more fantastic than some dusk or twilight shadows being cast on an ancient rock formation and turning the whole thing into a huge ink blot test for conspiracy theorists.
Open your mind not only to the possibilities and the potential wonders....but also to the very good chance that some of the things you believe in were never true to begin with. Complete and total bunk used to sell books and promote personal careers. The cosmos is neither the "we're the only life in the universe" scenario nor the "government is covering up everything for some sinister underground agenda" setup that their respective cheerleaders believe they are.