What are voltages at these points in this opamp circuit equal?
But if there is really large resisitance, shouldn't the volage also be very large?


Normally, a large resistance between two points means there's no strict relation between the voltages at the two points. They could be anything. One higher than the other, the other way around, or nearly equal, without a lot of current flowing. So there's no reason it should be one way or the other.

In this case, though, there's an amplifier connected so that its output controls the voltage at V2 (through the resistor divider made up by two resistors that you didn't give names to so I can't tell you which ones), and there's a negative feedback circuit established.

If V1 gets higher than V2, then the output of the amplifier goes up, which increases the voltage at V2.

If V2 gets higher than V1, then the output of the amplifier goes down, which reduces the voltage at V2. 

Only when the voltage at V1 and V2 are equal is the circuit stable.


  Second, I don't know why V2 is Vs.


Because the Voltage at V1 is Vs, and the feedback I just talked about forces V2 equal to V1.