Question: Doubting the Buddha's wisdom is like saying that what He teaches is false therefore, a person is not born in the Pure Land for doubting the Wisdom of the Buddha?  Not to doubt the Wisdom of the Buddha is equal to Shinjin?

Answer: Yes, not to doubt the wisdom of the Buddha means that you accept Amida Buddha knows better than you how to save you. That He devised the best method to save you, and so you follow exclusively His instructions in His Primal Vow.

To doubt the wisdom of the Buddha means that although you hear the requirements of the Primal Vow you think you know better than Amida and so instead of following the exclusive requirements of Amida – “say my Name perhaps even ten times” you think that you need to say Nembutsu many times or that you can combine Nembutsu with something else, like other practices. This means you doubt Ami...