What we call matter is actually a highly complex system of energy storage. In this sense, there is no difference between matter and energy. There is only energy, some of which is stored in material form. Men have recently learned how to release some of the energy stored in matter through the processes of nuclear fission and nuclear fusion. Light too is a form or dimension of energy which, like electrons and electricity, is involved in the process of energy transfer, e.g., transferring some of the sun's energy to the earth.
Space is a form of energy associated with matter.
Space-time is energy being released and expanding. Gravity is another form of energy associated with matter. Gravity and space are two poles of a cosmic energy field, one positive and expanding the other negative and contracting. Together they provide sufficient equilibrium for a universe such as ours to exist. Gravity and space in other words cancel each other out in our universe.