Oh, I’m so glad you have asked!
There are several scriptures which sum it up beautifully, the best known and most succinct being John 3:16 (the entire chapter should be read, for context).
“For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.”
John 3:16
in short, God who is holy and just and good made a way whereby He would satisfy His justice and yet save and redeem and restore to relationship with Himself, as a new creation, by the indwelling of His Holy Spirit, any sinful and hell-bound helpless repentant human being, without minimising or overlooking their sin, and with all the work being accomplished by Himself, through union with the life, death and resurrection of His Son, the Man, Christ Jesus, God incarnate, the second Adam, solely by grace through faith in Him alone.
Other scriptures which relate to the gospel of Jesus Christ include
“Moreover, brethren, I declare to you the gospel which I preached to you, which also you received and in which you stand, by which also you are saved, if you hold fast that word which I preached to you—unless you believed in vain.
For I delivered to you first of all that which I also received: that Christ died for our sins according to the Scriptures, and that He was buried, and that He rose again the third day according to the Scriptures, and that He was seen by Cephas, then by the twelve. After that He was seen by over five hundred brethren at once, of whom the greater part remain to the present, but some have fallen asleep. After that He was seen by James, then by all the apostles. Then last of all He was seen by me also, as by one born out of due time. For I am the least of the apostles, who am not worthy to be called an apostle, because I persecuted the church of God. But by the grace of God I am what I am, and His grace toward me was not in vain; but I laboured more abundantly than they all, yet not I, but the grace of God which was with me.
Therefore, whether it was I or they, so we preach and so you believed.”
1 Corinthians 15: 1-11
“For the grace of God that brings salvation has appeared to all men, teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly in the present age, looking for the blessed hope and glorious appearing of our great God and Savior Jesus Christ, who gave Himself for us, that He might redeem us from every lawless deed and purify for Himself His own special people, zealous for good works.
Speak these things, exhort, and rebuke with all authority. Let no one despise you.”
Titus 2: 11-15
“And you He made alive, who were dead in trespasses and sins, in which you once walked according to the course of this world, according to the prince of the power of the air, the spirit who now works in the sons of disobedience, among whom also we all once conducted ourselves in the lusts of our flesh, fulfilling the desires of the flesh and of the mind, and were by nature children of wrath, just as the others.
But God, who is rich in mercy, because of His great love with which He loved us even when we were dead in trespasses, made us alive together with Christ (by grace you have been saved), and raised us up together, and made us sit together in the heavenly places in Christ Jesus, that in the ages to come He might show the exceeding riches of His grace in His kindness toward us in Christ Jesus.
For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast.
For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand that we should walk in them.”
Ephesians 2:1-10
Perhaps this short video by Paul Washer will explain things in a way that is easily understood.