Jesus said that out of the mouth, the heart professes. It is not much of a leap at all to say that if you cannot articulate the Gospel, then your heart is in bad shape, and you have this promise that "Blessed are the pure in heart, for they shall see God." If your heart is anything but pure, you will not see God.
The Apostle Paul noticed the problem in the Southern Region of Galatia, to include Lystra, Iconium, and Pisydian Antioch, that they had lost the Gospel. His Epistle to correct the problem is the only one which does not include a thanksgiving for the church.
Beloved, if you lose the Gospel, you lose everything, you become anathema; condemned, lost, and doomed. So what is the Gospel?
Is it that God loves you and has a wonderful plan for your life? No.
Is it that God wants to have a relationship with you? No.
Is it that God created you with free-will to choose him? Heaven forbid!
Beloved, each of these has resulted in multitudes diving head-first into Hell expecting their idolatrous god to catch them...just because their made up god's name was jesus christ, that does not mean that he was mighty to save, just that he shared a name with Lord of Glory. There is only one Righteous God and Saviour, who besides him there is no Saviour.
If Paul was going to call the churches in Galatia condemned, then what ought he do? He should give a crystal clear Gospel presentation in order to correct those deceived and deceiving in Galatia.
Grace to you and peace from God our Father and the Lord Jesus Christ, who gave himself for our sins to deliver us from the present evil age, according to the will of our God and Father, to whom be the glory forever and ever. Amen. -Galatians 1:3-5 ESV
Let's break it down into its parts:
Grace to you from God... Grace is unmerited favor, that when we did not love God, he loved us. We had transgressed the Law of God, and justice called for our recompense, which when considered that the sin was against an infinite God, the punishment must also be infinite. Had we received mercy, we would have been given a reprieve from Hell but denied access to Heaven and God. Grace has made us more than conquerors, being made inheritors with Christ of every good thing, including a place at the table of the Lord.
Peace from God... We are by nature enemies of righteousness, storing up wrath for ourselves to be revealed from Heaven on the day of wrath, using God's name as a curse word to express our animosity towards him. Jesus Christ said that when we lie, we are proving that we are of our father the devil, for he is a liar, and the father of lies, and our will is bound to his to do what he desires.
Being an enemy of God is not a good place to be; fear not him who can only kill the body, but do fear him who after killing the body, is able to kill the soul in Hell, yes, fear him. He has sharpened his sword against the unrepentant, he has bent his bow with flaming arrows at his enemies. He has promised to make a complete end of his adversaries, and will pursue his enemies into the darkness. (Nahum 1)
Paul put it beautifully to Colosse, that we were alienated and hostile in mind towards God, doing evil deeds, but he has now reconciled us. In Romans 5, if we have been justified, then we are declared to have peace with God through Jesus Christ.
God our Father... Once justified, with grace and peace, we are adopted into the family of God. God is the just judge who will by no means clear the guilty. He is a jealous God, a consuming fire, his glory will not be shared, he hates sin and sinners (Psalm 11:5, Proverbs 6:16-19), and yet he is a good stronghold in the day of trouble; he knows those who take refuge in him.
Jesus Christ... The Lord of Glory, uncreated, perfect, sinless, holy, pure, God manifest in the flesh, a coequal Person of the Triune Godhead, the judge of righteousness; he holds the keys of death and Hell. He was dead, but he is alive; he was despised, but at the final trumpet, at the name of Jesus every knee will bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father. He too hates sin and sinners. (Hebrews 1:8-9)
Jesus Christ gave himself for our sins to deliver us... We were undone, a people of unclean lips, woe to us, we were without hope! We had sinned against Heaven and our souls were the cost. But Jesus Christ, under no obligation to save sinners or even associate with them, stepped out of Heaven, humbling himself to be born in a cave and laid in a feeding trough, then he lived a perfect sinless life, tempted in every way possible but never succumbing, and then humbled himself to death on a cross. The wrath of God was pointed at us in the form of flaming arrows when Jesus Christ took those arrows willingly, and the Father held nothing back and it pleased him to crush his only begotten Son who was made sin for us, because God hates sin and will not allow it into his presence.
In his death we have found peace, in his resurrection we have found life. When we are buried with him in death, the death of our old self, and raised to walk with him in newness of life, his life, then we are delivered. We are reborn, not of blood nor of the will of the flesh nor of the will of man, but of God.
from this present evil age... The system in which God is patient towards all mankind, not that he is slack in his promises, but if he did kill all sinners, then many whom he has predestined for salvation would not arrive at repentance. (2 Peter 3:9) Do not presume on the riches of God's kindness and forbearance and patience, since God’s kindness is meant to lead you to repentance.
according to the will of our God and Father... God, being omnipotent, omniscient, and omnipresent is not slave to the wills of men or the constraints of time. He created man to fall in order that his glory be displayed all the more brightly. His mercy, patience, love, kindness, wrath, vengence, hatred, goodness, ingenuity and a myriad of other attributes are demonstrated in the suffering death and resurrection of Jesus Christ. God's perfection was planned before eternity to be demonstrated in one culminating event on Calvary's cross.
God willed the events, he placed Simon of Cyrene in the right place to be the Hamite called to carry the cross of a Semite by Japhethites. Had Christ died inside of the city then hundreds of years of scape-goat prophecy would have been ruined. Had Christ died in any way other than on a cross with all of his bones intact, amongst thieves, and laid in the tomb of a rich man...then we would just throw the book of Isaiah away.
If there were any other way to be saved, then Christ died in vain. And saved from what? We are saved from Hell and sin and despair, but beloved, these are piddly in comparison to the true danger to our eternity, which is the wrath of a holy and offended God, but there is now no condemnation for those who are in Christ Jesus.
to whom be the glory forever and ever... Your sins are forgiven for the namesake of Christ. Our sins were blotted out for the sake of God. The purpose of Calvary was to show that the God of Wrath and the God of Love are one, and that these entirely contradictory titles are reconciled in the death of the Son. Grace and truth have met; righteousness and peace have kissed each other. Christ did not die primarily to save sinners, he died primarily to redeem the name of God which was blasphemed amongst the nations by the actions of men who are created in the image of God and were and are presenting a blasphemous picture of him.
Jesus Christ demonstrated that God is perfect in every good thing, his hatred is perfect, his wrath is perfect, his love is perfect, his actions are perfect, and his plan is perfect. He is God, and we are not.
This is the Gospel, the whole Gospel, and nothing but the Gospel. Christ came to give life and more abundantly, indicating that before we had the life of Christ, we had death and an overabundance of it.
Know it, live it, preach it.