If anyone can debunk this one, I might become a Christian.
Out of boredom, I will accept your challenge, although you seem to be a drive-by poster.
People like Adam Green have a theory that Christianity was invented by Jews in order to pacify gentiles ("turn the other cheek", "love your enemy", etc).
If it did, how did that work out? The Romans razed Jersualem and the Second Temple to the ground, causing the diaspora. That theory is flawed considering that Jews were the first converts to Christianity, not gentiles. If it was "invented" to pacify gentiles, it would have been aimed at the gentiles from the start.
Second, if it were an invention, the Jewish leaders wouldn't have been antagonistic toward Jesus. The Sanhedrin is responsible for accusing Jesus of blasphemy and handing him over to the Romans. The Sanhedrin persecuted the apostles and early Christians. If the goal was to spread Christianity to the gentiles, they did the exact opposite. The Jewsish leaders tried to stamp out Christianity.
Third, according to tradition, all the apsotles except John were martyred (and they tried to boil John alive). They would not have been willing to give up their lives for a lie. They would have been given the choice to renounce or die.
Fourth, they wouldn't have picked someone as obscure as Jesus. He was a carpenter by trade. He never held any political office. He wasn't a great military leader. He left behind no heirs. He didn't have any influence beyond his followers. From the outside, he was a nobody.
If it was some kind of deception, it was the most successful deception in history. But the odds of such a deception actually succeeding to become the most prolific religion in history is so astronomically high as to be impossible.
Can this be debunked?
Yes, because it is an argument from silence. You're attempting to make a claim based on the absence of evidence, rather than the presence of evidence. The onus is not on us to prove that it isn't true, it's on you to "prove" that it isn't. And since it's all just speculation, it can never be proven to be true.