a mortal sin

Never once in our relationship, I was proud to think, had I ever even been tempted to commit a single mortal friendship sin: being competitive, gossiping, or backstabbing.

我曾骄傲地认为，对我们的友谊，我都一直没有被”凡夫俗子“友谊中的任何罪恶所诱惑：好胜、散布谣言或背地里说坏话。

To be forgiven for committing a mortal sin, one must be extremely penitent.

为了要得到宽恕,犯下这些罪的人必须有很大的耐心.

Maybe I can understand all that, but what a mortal sin it is to cheer for all the innocent souls we lost on that fateful day.

或许我能够明白那一切，但这是多该死的罪行，为我们在那悲惨的一天失去无辜生灵而喝采。

it's not considered a mortal sin if you like someone in your own gender or if you aren't comfortable being male/ female/ etc. Proof of this is the LGBT Pride Day held in every city.

如果你喜欢同性或者你觉得自己作为一个男人/女人哪里不对，都不会被认为是弥天大罪，证据就是每座城市都会举办LGBT骄傲日。

Adultery is a mortal sin.

通奸是不可饶恕的罪孽。

Once she would have thought this omission a mortal sin but, somehow, staying away from church did not seem so sinful now as it formerly had.

要是在以前，她会把这种疏忽看成莫大的罪过，可是现在，不进教堂就好像并不那么有罪了。

But I was told that taking on overdrafts and even mortgages was akin to committing a mortal sin.

但有人告诉我，透支乃至抵押贷款都无异于犯下不可饶恕的大罪。