Everything should work if you follow Ken's earlier advice. Ditch the on/off switch - I don't quite understand how you have wired that in but I think that is screwing things up - and you don't need it anyway. Before you fly in earnest you will need to ditch the ESC as well because it is too small (5A) to cope with that motor (it'll draw 8-10A - get a Pixie 10P). But, in the meantime that GP ESC will work well enough for you to test the system.

Connect motor to ESC, connect ESC to Ch 3 on Rx, turn on Tx, with throttle lever at zero, THEN connect battery to ESC when, and only when, you are ready to test/fly.

I have a feeling those GP ESC's have a peculiar arming sequence - read through the instructions which came with it. You should have the throttle at zero position when you connect the battery. THEN you need to move the throttle to full and hold it there for a few seconds - you should hear a faint high frequency beep; move the throttle back to zero - and then you'll be ready to go.

Try that, and let us know the result.

Cheers, Phil