Use a comma before a quote, so that is right.
The period should be outside the quote. It should only be inside the quote if the original quoted text contained a period.
There is no doubt about the written evidence [in the sutra] of, “peace and security in this lifetime”.
John said, “I went to the store yesterday.”
John said, “I went to the store yesterday.”.
I’ve learned that both of the above are acceptable. Personally I do it the first way, without adding an additional period outside the quote. If the quoted text ends with a question mark, then the period outside the quote is needed.
John asked, “Should I go to the store tomorrow?”.