Venus and Mercury are too hot for liquid water. Mars is too cold, although there is ice. The Earth is 'just right', which allows for life to occur here. Perhaps in the distant past, life existed on Mars, when it was hotter. Now it is inhospitable.
Life is key.
As we saw from Daisyworld, life can change the surface conditions of a planet. We have an O 2 -rich atmosphere, and little CO 2 . Had Venus developed life, it might have evolved to a life-friendly planet. Most of the planets revolve around the sun in a orbit with an axis parallel to each other, as do their rotations. The Moon was formed by a large impactor Meteorites and asteroids are from the asteroid belt, between the Earth and Jupiter.