If Yahweh's Name was replaced in the Scriptures back before the time of Yahshua, why did Yahshua not say something about it during His earthly ministry? Or did He?
ANSWER:
For one thing, when Yahshua came to earth in the form of a man, Judaism was not using Yahweh's Name, BUT they had not literally replaced it in their Scriptures. They merely read a substitute, such as "Adonai" or "HaShem" when they came to YHWH; all instances of His Name in the Scriptures were replaced with written substitutes later on AFTER Yahshua's return to the heavens.
However, even as they are not today, when Yahshua was on earth, many were not using Yahweh's Name or upholding it, and Yahshua did go out of His way to clarify that 1) He came in His Father's Name. John 5:43. 2) He came to declare His Father's Name. John 17:6, 26. He also asked the Father to esteem His Name. John 12:28. Furthermore, He said that 1) We should ask things in Yahshua's Name. John 14:13-14. 2) Those who truly love Him would be hated for His Name's sake. Matthew 10:22. (Notice that when one asks in YAHSHUA'S Name, he is simultaneously asking in YAHWEH'S Name, and when he is persecuted for YAHSHUA'S Name's sake, he is at the same time being persecuted for YAHWEH'S Name's sake, as the Name YAHSHUA is the Hebrew way of saying "YAHWEH our Salvation" or some other close equivolent.)
For more about the Names of the Father and Son, Click here.