It is our firm conviction that a step forward has been taken.

我们坚信已经向前迈进了一步。

《柯林斯英汉双解大词典》

Firm conviction is the rose that never fades.

坚定的信念是永不凋谢的玫瑰。

youdao

She had a firm conviction that she was always right.

她坚信自己总是正确的。

youdao

This is my firm conviction that shall continue to guide me.

WHITEHOUSE: State Dinner for German Chancellor Merkel

He was guided by the firm conviction that many of the ills afflicting the church could be traced to a misreading of the reforms of the Second Vatican Council.

NPR: Pope Legacy: Teacher Who Returned To Church Roots

And I think Prime Minister Gillard and I both share a very firm conviction that the violence that's been taking place and perpetrated by the government in Libya is unacceptable.

WHITEHOUSE: President Obama and Prime Minister Gillard of Australia