Dr. Flowers conflated the lump of clay with Israel. That lump of clay was not Israel, but all of mankind.
Or does not the potter have a right over the clay, to make from the same lump one vessel for honorable use and another for common use? What if God, although willing to demonstrate His wrath and to make His power known, endured with much patience vessels of wrath prepared for destruction? And He did so to make known the riches of His glory upon vessels of mercy, which He prepared beforehand for glory, even us, whom He also called, not from among Jews only, but also from among Gentiles. As He says also in Hosea, “I WILL CALL THOSE WHO WERE NOT MY PEOPLE, ‘MY PEOPLE,’ AND HER WHO WAS NOT BELOVED, ‘BELOVED.’”[Romans 9:21-25]
That lump can not be solely Israel. As you can see, the Gentiles were also included in that same lump of clay. All mankind is included in that lump of clay. All were fallen in Adam. God chose His ppl from that same lump of clay. That is who the vessels of mercy are, the elect of God. The vessels of wrath were in that same lump and God justly left them in their fallen state.