Jiang Chen wasn't very sure about it.
It wasn't that he wasn't confident about defeating Gao Tiange, but he wasn't sure he could control himself and not kill Gao Tiange while defeating him.
He hadn't yet completely mastered the first movement of the Sword Method of Ksana. Under such tricky conditions, it would be extremely difficult for him to defeat his rival without killing him.
No one had ever been killed in the competition of the Sacred Institute. Such fights usually ended when one of the two was defeated.
Even Gao Tiange only had the will to fight, not the will to kill.
It would be against his beliefs to exert a killing movement in order to win a fight. It wouldn't do him any good, either.
Most importantly, even if he won that way, it wouldn't be a victory he was proud of.
Unless they both agreed to a life-or-death fight, if he made an all-out attack while Gao Tiange was holding back, people would regard him as a dirty fighter.