We must have faith in the masses.

要相信群众。

《新英汉大辞典》

We must have faith, for this is the foundation;

我们必须有信心，因为这是基础；

youdao

Measure always more than difficult, therefore, we must have faith.

办法总比困难多，大家要有信心！

youdao

"To the Irish people I say simply this: We should not underestimate the scale of our economic problems, but we must have faith in our ability as a people to recover and prosper once more, " he said.

BBC: Republic of Ireland confirms EU financial rescue deal

We know that you are only one man and we must all believe, have faith, and support you in your endeavors.

WHITEHOUSE: Discussing the Economy in Albuquerque

We must keep faith with all who have risked life and limb so that we might live in freedom and peace.

NPR: Text of Bush's State of the Union Address