The word GOSPEL by definition means GOOD NEWS. So when we act upon the gospel, you believe, preach and spread the good news.
So what is the good news?
The proto gospel is the foretelling of the good news of Jesus Christ which happened thousands of years before Jesus Christ appeared on the earth in the flesh.
The gospel of Jesus is the good news of His actual coming and what it did for all of humanity.
The gospel of the Holy Ghost is the good news that we are not left alone in a dead religion, but can have the Spirit of the Living God within us in supernatural power.
These three good news events, comprise the WHOLE GOSPEL.
THE PROTO GOSPEL
From various sources: The proto-gospel or protoevangelium is God's statement to the Serpent in the Garden of Eden about how the seed of the woman would crush the serpent's head: "And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel." (Genesis 3:15, KJV)
Protevangelium is a compound word of two Greek words, protos meaning "first" and evangelion meaning "good news" or "gospel". Thus the protevanglium in Genesis 3:15 is commonly referred to as the first mention of the good news of salvation in the Bible. Strictly speaking, the protevangelium refers to the last part of Genesis 3:15, "it shall bruise thy head and thou shalt bruise his heel."
According to H. C. Leupold, this passage uses a zeugma in the word "bruise", which may be translated "it shall crush thy head and thou shalt bruise his heel." Because of the grave nature of the context, the fall of man, this passage describes more than just a man stepping on a snake's head.
The reference to the seed of the woman as Christ is believed to relate to the Virgin birth of the Messiah, as well as the Divine nature of the trinity with the Human nature of Christ. Old Testament scholar Derek Kidner describes the Protevangelium as "the first glimmer of the gospel." Several of the early Church fathers, such as Justin Martyr (160 AD) and Irenaeus (180 AD), regarded this verse "as the Protoevangelium, the first messianic prophecy in the Old Testament."
THE GOSPEL OF JESUS
The gospel of Jesus Christ is the good news that the only begotten Son of God came in the flesh through a virgin birth, was crucified for our sin, and was resurrected on the third day, ascended into heaven, and now sits on the right hand of the Father as a propitiation, or atonement for our sin.
All of humanity now has a way back to God through Jesus Christ. Up until this time there was no way back to the Father and all died in their sins. Books are written about the details of this atonement, and exactly what it means to us, but the key word here is SALVATION. Jesus died that we may be saved, and this is the good news of all time. BUT WAIT - there's yet more to come.
THE GOSPEL OF THE HOLY GHOST
Jesus said:"John baptizes with water, but I will baptize you with the Holy Ghost"
Jesus also made the promise that when He goes away he would not leave us alone, but would send the comforter which is the Holy Ghost.
As recorded in the second chapter of the book of acts, this first happened on the day of the feast of Pentecost while believers were praying and waiting on God for further instruction and guidance, and happened shortly after Jesus ascended unto the Father.
It was a mighty outpouring and was even seen as fire that came upon the house they were in, and was unlike anything that was ever seen before. Believers were filled with the Holy Ghost and performed supernatural acts of God both then and ever since.
However there is not much written in history about this mighty outpouring past the first century church, but it probably still occurred on an individual basis, just not appearing in groups of believers.
But all this changed around the turn of the 20th century. A renewal of the same outpouring in the book of acts happened again at Azusa street, Los Angeles, California in 1906. All of the mighty acts of God as recorded in the book of acts happened again among hundreds of believers in the same like manner as it happened at the upper room.
One remarkable feature that was different was a Glory cloud that rested on that building at Azusa street, that remained for around 2 years. This outpouring ended when the Glory cloud left, and men began to usurp the leadership of the Holy Ghost, as what usually happens with any movement or outpouring of God.
BUT THE GOOD NEWS OF THE HOLY GHOST REMAINS TODAY!
With the Holy Ghost moving in us and through us, we are given this same supernatural power to exercise ALL of the gifts of the spirit as recorded in the New Covenant scriptures. This is how we "run our race" or "walk out our salvation" as Paul put it.
But even more than that, these supernatural gifts are for the winning of souls, for deliverance from devils, and to help other believers along the Matthew 7:14 path.
If you are not walking in this supernatural power of God, you are not walking in the WHOLE GOSPEL of God. Believe upon Jesus Christ today for the fullness of what He has for you. Pray in ernest, submit yourself to him in total submission. He will put His Holy Ghost within you.
There are many scriptures in the New testament that refer to the outpouring and need of the Holy Ghost. There are three different lists of the gifts of the Holy Ghost:
The three main passages describing the spiritual gifts are Romans 12:6–8; 1 Corinthians 12:4–11; and 1 Corinthians 12:28. We could also include Ephesians 4:11, but that is a list of offices within the church, not spiritual gifts, per se. The spiritual gifts identified in Romans 12 are prophesying, serving, teaching, encouraging, giving, leadership, and mercy. The list in 1 Corinthians 12:4–11 includes the word of wisdom, the word of knowledge, faith, healing, miraculous powers, prophecy, distinguishing between spirits, speaking in tongues and interpretation of tongues. The list in 1 Corinthians 12:28 includes healings, helps, governments, diversities of tongues.
There is also the fruits of the spirit which are obtained through the working of the Holy Ghost within us:
Galatians 5:22-23 King James Version (KJV)
22 But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,
23 Meekness, temperance: against such there is no law.