Original sin is an invention by one sect.That's our condition of "Original Sin", the idea to sin comes from this condition, but we retain the power to thwart the ideas that seemingly 'pop' into our head. Adam didn't have such a thought 'pop' into his head, to eat the forbidden fruit. He consciously chose to do it. That's the type of sin he committed, turns out 'on our behalf'.
But Original Sin doesn't force someone to disbelieve in Jesus. We have the power to thwart that idea to not believe.
It is not true.