I believe in the institution of marriage.

我相信婚姻制度。

《柯林斯英汉双解大词典》

I believe in the maxim "if it ain't broke, don't fix it."

我相信这句格言：“如果它没坏，不要去修理它。”

《柯林斯英汉双解大词典》

There are a few technical difficulties, but I believe in the next five to ten years we will be installing commercial marine turbine farms.

存在一些技术上的难题，但我相信在未来的5到10年里，我们将会建设商用的海洋涡轮发电场。

youdao

They believe the simian immunodeficiency virus,S.I.V., probably crossed from chimpanzees to humans in the last one hundred years.

VOA: special.2009.09.08

He says, "I believe in the practice and philosophy of what we have agreed to call magic, in what I must call the evocation of spirits, though I do not know what they are."

他说我相信我们所称作的,关于魔法的实践和哲学，我认为那是对灵魂的召唤，尽管我并不知道它们是什么“

耶鲁公开课 - 现代诗歌课程节选

Why do I believe in the existence of atoms so small that I can't see them?

为什么我相信原子的存在,它是如此之小,以至于我根本就看不到它们

耶鲁公开课 - 死亡课程节选

But I believe in the American system of justice that he is presumed innocent.

CNN: Alaska senator on charges: 'I am innocent'

If I believe in the Constitution, that it will work, then I must believe in you.

CNN

As I said on this stage two years ago, I believe in the power of the free market.

WHITEHOUSE: President Obama Tells Wall Street to Back Reform