What is the "gospel" anyways?

There are some Lord's days when by the next morning, I have to think for a minute to remember what the messages were about. It's not like I wasn't paying attention at the time; it's just that for whatever reason it doesn't stick in my mind. God willing, this won't be one of those days; I think it's changed for the better how I will present the gospel at every future opportunity.

We were asked "if you were put on the spot in a meeting like this and asked to describe the gospel, what would you say?" You'd expect that to be a no-brainer, but what is perhaps the most natural response is at best incomplete and at worst, a complete distortion of the gospel's intended purpose. "Believe in the Lord Jesus and you will be saved." It sounds right, but it's really not. That statement is the gospel's promise, but it's not the gospel itself. He took us to 1 Corinthians 15:1-4:

"Now I make known to you, brethren, the gospel which I preached to you, which also you received, in which also you stand,... that Christ died for our sins according to the Scriptures, and that He was buried, and that He was raised on the third day according to the Scriptures."

One can take the time, after saying the above, to describe what sin is, who Christ is, and the significance of His death, but the central nature of the gospel is what God has done. To say that the gospel is "believe in Christ" incorrectly focuses the hearer's attention on himself rather than on God, who has done everything necessary for anyone to have their broken relationship with Him restored. There's nothing we can or should do to obtain this mending, because He has done it all. All we need do is take Him at His word. Sacraments are meaningless when it comes to salvation, as are ecclesiology, eschatology, what you think about alcohol and how long you think men's hair should be. All that really matters is whether you're simply trusting in the finished righteousness of Christ or your own good works, church attendance, moral living, etc. If you're trusting the latter then you are not going to be a happy person, and for good reason, because no one can live up to the absolutely perfect obedience that God's justice requires. You can't even get the flame of faith started without the heart surgery that the Spirit carries out at His own discretion, let alone keep the fire burning. If you're trusting in Christ's already finished work, your hope is secure. If you've been given the heart transplant required to believe, then you're going to be so amazed and attracted to that sacrifice that you're going to want to obey Him and serve Him in every nook and cranny of your life even though you could do anything and He will not turn His love away. The freedom we have in Christ means that even we can never sin away His grace, sin is what our Spirit-installed, Christ-enamored heart most despises.

It's a mystery of the sovereign grace of God that the only people who have the blank check of grace and free forgiveness are also the very same people most loath to use it.