How gravity acts equals on all bodies irrespective of their masses According to Einstein's theory of relativity, gravity is a space time fabric: it acts equally irrespective of masses; space is pushing objectives down. If it happens, why are gasses upper in the atmosphere and liquids on Earth  and Earth consists of solids? Why cannot gasses and liquids be mixed together at all levels?
 A: First of all, the fact you're referring to, that gravity "acts equally irrespective of the mass" of the object, does not arise just with General Relativity, but was already discovered by Galileo in the 16th century. A 1kg object and a 10kg object, thrown from a tower, will land at the same time at the bottom of that tower. According to the legend, this is the experiment Galileo performed, from the leaning tower of Pisa. (The friction with air will actually prevent this experiment from working properly, but it will work in vacuum!)
This means, concisely, that all object fall with the same acceleration due to gravity. This acceleration, on Earth, is roughly equal to $g=9.8 m/s^2$.
However, this is about accelerations, not forces. Because force equals mass times acceleration, $F = ma$, then the "force of gravity", which is also called weight, does depend on mass: $F_{weight}= mg$.
Now, force is the measure we're looking for when determining how different things interact, how much they can "push towards the bottom".
