As the proverb says...

正如……(谚语)所说。

As the proverb says, no pains, no gains.

正如谚语所说：不劳无获。

As the proverb says, honesty is the best policy.

正如谚语所说，诚实为上策。

Yet, as the proverb says, "the sage is not happy."

然而正如谚语所说，“智者是不快乐的。”

As the proverb says kid is the centre of a family.

就像谚语说的孩子是一个家庭的中心。