The whole movie was spent demonstrating how powerful Kylo Ren is. He stopped a blaster bolt mid-air, and continued to walk around and have a conversation with no effort. He used the force to read minds. Last, but definitely not least, he continued to fight Finn ( a melee fighting prodigy in his trooper training) and Rey (who is also obviously strong with the force) while he had just taken a bowcaster shot to the gut. Previously in the movie, the bowcaster shot was shown to send people flying.
So please uninformed, false Star Wars fan, please tell me again why you think Kylo Ren is weak?