Then, how should we take the biblical verse which records the coming of the sons of Israel? Rev. 7:4 states that out of every tribe of the sons of Israel there would be sealed 144,000 at the time of the Second Coming. What does this mean?

Originally, the name "Israel" was received by Jacob after he prevailed over the angel at the ford of Jabbok (Gen. 32:28). In other words, "Israel" means the people of God who have triumphed in faith and does not necessarily mean the lineal descendants of Jacob. Matt. 3:9 and Rom. 9:6 clarify the true definition of Israel.