A simple and Biblical way to understand it:
1. God — We were created for Him.
God is holy, loving, and our Creator. He made us to know Him and live under His authority.
“In the beginning, God created the heavens and the earth.” — Genesis 1:1

2. Man — We have all sinned.
The problem is that every person has rebelled against God. Sin separates us from Him, and we cannot save ourselves through good works or religion.
“For all have sinned and fall short of the glory of God.” — Romans 3:23
“For the wages of sin is death…” — Romans 6:23

3. Christ — Jesus did what we could not do.
This is the heart of the Gospel. Jesus Christ, God's Son, became man, lived a sinless life, died on The Cross for our sins, and rose again from the dead.
Paul summarizes the Gospel this way in 1 Corinthians 15:3–4:
“Christ died for our sins… He was buried, and He was raised on the third day.”
Jesus took the punishment sinners deserved so that those who trust in Him can be forgiven and reconciled to God.
“But God demonstrates His own love for us in this: While we were still sinners, Christ died for us.” — Romans 5:8

4. Response — Repent and believe
The Gospel is not merely information to admire. God calls us to respond.
We must turn from trusting ourselves and turn to Christ, placing our faith in Him alone for salvation.
“Repent and believe the gospel.” — Mark 1:15
“Believe in the Lord Jesus, and you will be saved.” — Acts 16:31