David J. Stewart has no clue what the biblical Gospel is. He frequently refers to 1 Corinthians 15:1-4, but this is not "the Gospel." "But," you will argue, "Paul says, 'I make known to you, brethren, the gospel which I preached to you.'" Yes, he does, but you misread this passage. Nowhere does Paul identify that which he says in verses 3 and 4 as "the Gospel." You make this leap in logic by trying to connect these verses to his use of "Gospel" in verse 1. If he were indeed saying this is the Gospel, who do we trust and believe to rightly identify what the Gospel is? Paul or Jesus? Who is the Author and Founder of Christianity? Paul or Jesus? What Paul identifies here as "of first importance" are the essentials of the faith, that which all believers in Jesus the Messiah must hold in unity. Jesus declared to us what "the Gospel" is in Mark 1:14-15. Believe the Lord Jesus over that which originates with Martin Luther!
"Now after John had been taken into custody, Jesus came into Galilee, preaching the gospel of God, and saying, "The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel.""
"The time is fulfilled" refers to the beginning of the 70th week of Daniel's prophecy, initiated by Jesus' baptismal anointing. "The kingdom of God is at hand" refers to Daniel 2:44 in fulfillment thereof. The "Good News" is that Yahweh's anointed King of the whole Earth has come, and the long-awaited Kingdom is in our midst.
Rabbinism, Zionism, and Dispensationalism ignore, deny, and reject the teachings of the Holy Scriptures in favour of Jewish myths. The interpretations of the Pharisees in Jesus' day were constantly refuted and corrected by the Lord Jesus. These three groups are looking for a physical kingdom where ethnic physical Israel rules over all other nations, but God's Word teaches no such thing!
After everything Jesus had said and taught, the apostles still did not get it. "So when they had come together, they were asking Him, saying, "Lord, is it at this time You are restoring the kingdom to Israel?" (Acts 1:6). They were with Him for three and a half years and did not listen to a single thing He had to say concerning the Kingdom. "Now having been questioned by the Pharisees as to when the kingdom of God was coming, He answered them and said, "The kingdom of God is not coming with signs to be observed; nor will they say, 'Look, here it is!' or, 'There it is!' For behold, the kingdom of God is in your midst."" (Luke 17:20-21). "Jesus answered, "My kingdom is not of this world. If My kingdom were of this world, then My servants would be fighting so that I would not be handed over to the Jews; but as it is, My kingdom is not of this realm."" (John 18:36). I think come Pentecost the apostles finally understood about the Kingdom because there appears to be a change in their understanding. Otherwise, how would they preach about the Kingdom of God if they did not fully understand what Jesus had been conveying, even in His parables?
Yes, the suffering, death, and resurrection of Jesus were prophesied long ago in the Old Covenant. However, these were not identified by the Lord Jesus as "the Gospel." They had to happen, and they did, and they are part of the Gospel, but they are not what Jesus identified for us as "the Gospel." We would do well to pay attention to the words of Jesus and accept them as true than to elevate Martin Luther's redefinition of "the Gospel" using the atonement. In Jesus' parables about the Kingdom, He says the King sent His own Son and the children of the Kingdom (who would be cast out for their rejection) killed Him. The atonement is meaningless without that which it conveys.
What people like David J. Stewart call "the Gospel" is actually the atonement. While the atonement is true and is part of the Gospel, it alone is not the Gospel. The atonement grants us entrance into this Kingdom through faith (trust) in Jesus and His work on the cross, as well as by repentance and obedience. The Bible only has to say something once for it to be true. So how to so-called self-identified "Christians" who say repentance and obedience "are works" and have "no part with salvation" deal with the fact that we are repeatedly told to "Repent" and "Obey"? At the end of the Instruction on the Mount, Jesus addresses obedience and disobedience to His teachings. Repeatedly throughout the entire New Covenant, it is said "If you love [Jesus] you will [obey His] commandments/teachings."
If you call yourself a Christian, STOP listening to what preachers tell you and START reading the Scriptures for yourself and believing what they say. If a preacher tells you something that is blatantly in contradiction to the Word of Yahweh, then you need to reject it and conform to the Scriptures. If you blindly trust what these preachers tell you, like the Pharisees of old, they will prevent you from entering the Kingdom and make you twice the children of Hell that they are! Preachers, theologians, and "scholars" are the modern day Pharisees, Sadducees, and Scribes. Beware their leaven!