There are many approaches to Quantum Gravity. We have string theory (ST), loop quantum gravity (LQG), causal dynamical triangulations (CDT), causal set approach (CSA) and many others. There are some common features for all of these theories. We discussed them briefly. We claim that the mathematical apparatus for Quantum Gravity is hidden in foundations of ST, LQG and CSA. We formulate the RT-paradigm and we wrote a list of open issues.