tantamount

1. ADJ If you say that one thing is tantamount to another, more serious thing, you are emphasizing how bad, unacceptable, or unfortunate the first thing is by comparing it to the second thing. 無異于的[正式] [v-link ADJ 'to' n/-ing]

What Bracey is saying is tantamount to heresy. 布里斯正在說的無異于異端邪說。