I sincerely believe that this is the right decision.

我由衷地认为这个决定是正确的。

《牛津词典》

In fact, I sincerely believe that she also enjoyed it.

事实上，我坚信她会很乐意接受。

youdao

For example, you could say: "I sincerely believe that I'm the best person for the job."

比如，你可以说：“我认为我是这个职位的最佳人选。”

youdao

The people who think it's okay have every right to say that they believe, if they really, sincerely believe it's okay, they are committed to an ethics of autonomy.

认为没问题的人,绝对可以说他们相信…,如果他们是真的相信没问题的话，他们是真的遵循自治道德的。

耶鲁公开课 - 心理学导论课程节选

We sincerely believe the most important thing in turning your dream into reality is getting underway.

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Some of you sincerely believe that the only solution to our economic challenges is to simply cut most government spending and eliminate most government regulations.

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