Gotta dissent from this op. He's got some of the basics correct but digressed into peripherals and, from the outset the speaker in that video has the meaning of the word "gospel" wrong. Here's why:
The word "gospel" is generally understood as "good news," but that is not quite correct. It's not quite correct because it is incomplete. The Greek word for "gospel" is "euangalion." An evangelion is a form of good news, not just any and/or all good news. The Greek word for "good" is "kalon," and the Greek word for "news" is "akoe." That means the ordinary Greek phrase for regular, commonly occurring news that is good is "akoe kalon," NOT "euangelion."
An evangelion was a specific kind of news. It was a term used in the Greek and Roman cultures, not a term used in Israel. The Greeks and Romans would make a public proclamation anytime a noted leader accomplished a task deemed to be heroic. In Rome the practice of evangelions was reserved to announce great victories by Roman generals or the deification of a Caesar. In other words, when the writers of what we now call the New Testament used the word "gospel," or "euangelion," they were appropriating a pagan term. They were not just appropriating a pagan term; they were appropriating a pagan term used by their oppressors to subjugate the Jews. This use of the term "euangelion" would have been provocative to the Jewish audience, at best, and reprehensible to the Jewish hearer at worst. It was all the more controversial to the Gentile and especially the Roman hearer because of the Christian gospel's content.
The gospel the apostles and New Testament era Christians preached was this: Jesus is the anointed one of God and he is God. Not only is he God, but he has done something that not even Caesar (in his faux divinity) can do: defeat death, come back from the grave, and sit with God on God's throne. The Roman leaders lost their mind when they heard this. They arrested Christians, covered them in pitch, rammed a pole up inside them, and then - while they were still alive - lit them on fire to be used as city nightlights.
In Greek and Roman cultures humans and gods were completely different beings. A human could never become a god. Even when a god bred with a human the progeny was a demi-god, not a full-fledged god. Dei-gods died. They were not immortal. When a Roman general or Caesar was deified, it did not mean the man was literally turned into a god. Such a thing was rationally impossible. It would be like turning an apple into an orange, or an apple into a diamond. When a Caesar was deified, he was promoted to a position whereby he was no longer relegated to the realm of Pluto, the god of the underworld, where ordinary people went when they died. A deified person got to live in the Elysian Fields at the foot of Mount Olympus. He was still dead. He was still just an ordinary man, still subject to death, and there was nothing he could do about either condition.
Jesus, on the other hand is God, has defeated death, and he is seated with his Father God. As a consequence of his defeating death and resurrecting, something Caesar could not do, Jesus is now King of all kings, Lord of all lords, and the Savior by which anyone and everyone who believes can be saved from sin, death, and the wrath of God coming upon all who deny the Son (which would include Caesar). In other words..... Caesar had to bow to Jesus! Again, this drove the Roman leaders nuts. Just as the gospel had angered the Jewish leaders because they had to bow to Jesus, the Romans responded in kind. What was a stumbling block for the Jew was foolishness to the Roman because humans cannot literally be The God, and they cannot come back from the grave, and Caesar bows to no one.
The reason this is important is because any definition of the gospel that does not include Jesus being the resurrected King of all kings condition is a different gospel.