He was convinced that I was part of the problem.

他确信我就是问题的一部分。

He became convinced of the need for cheap editions of good quality writing. [+ of]

他开始相信大众对优秀作品的普及本有需求。

I'm not convinced.

我还是不很信服。

He was a convinced Communist.

他是个坚定的共产主义者。