What would happen to bodies if molecules stopped repelling each other?

There would be a collapse, i.e. uncontrollable compression of particles of bodies to the center of mass and, for example, the Earth would turn into a black hole. Huge masses, such as the Sun and other stars, would also collapse into black holes before they even had time to run out of their fuel. Substance in the form in which we are used to seeing it would not be if there were no repulsion between the molecules. The forces of molecular repulsion are precisely what prevents this terrible outcome.