There are 2 different factors to this answer: Gravity, the force that pulls and Inertia, the force that pushes. To be a bit more detailed, Inertia is the reason that we are all alive, but so is Gravity. They work work together, yet separately since they are opposite forces. If we didn't have Gravity, we would've gotten throw across space and time. If we didn't have Inertia, we would've been pulled into one spot in space and would've just been there, forever.