The word ‘gospel’ means “good news”, for it is good news for sinners that their sins can be washed away completely in the sight of the holy God to enter His presence and live with Him for all eternity.
Because God is so pure and so good and so perfect that He cannot allow any imperfection–even the smallest tiny little stain–into His holy presence in Heaven. “God is Light; in Him there is no darkness at all.” (1John 1:5)
Sin is any disobedience towards God in any way. God is our Creator, and so He deserves to be worshipped and loved by His creatures with all of their heart, soul, mind and strength. He has given His Law of commandments and rules to be obeyed and followed for someone to be in right relationship with Him. Sin is the breaking of God’s Law in rebellion against Him. God’s just and righteous response to sin against Him is wrath and punishment and condemnation. “Because of your stubbornness and unrepentant heart, you are storing up wrath against yourself on the Day of God’s Wrath, when His righteous Judgment will be revealed.” (Romans 2:5)
Jesus said that in order to enter into the Kingdom of Heaven, you must “be perfect as your heavenly Father is perfect.” (Matt 5:48) If God the Father is perfect, then to get into Heaven you must be perfect in order to dwell with a perfect God. If God judged you on the basis of the 10 Commandments, would you be guilty or innocent before Him? Would you go to Heaven or Hell for all eternity? (By the way, it was Jesus Himself who taught that Hell is eternal punishment of unquenchable fire.)
The Bible says that “all have sinned and fall short of the glory of God” (Romans 3:23) and “there is no one righteous, not even one… there is no one who does good, not even one” (Romans 3:10,12).
It is through faith alone in Jesus Christ alone that saves a person. A person must trust completely in Jesus, surrendering their life under His Lordship. Saving faith is placed in WHO Jesus is and WHAT He has done: As the Son of God, He is the eternal God who became flesh and dwelt among us a human being. Jesus is fully God and fully Man, and as a human He lived a perfect life before God the Father in order to represent sinful humans as a substitutionary sacrifice upon the cross. Just as lambs and goats were sacrificed on altars to satisfy the wrath of God over sin, Jesus is the perfect Lamb of God who hung on the altar of the cross to completely take away the sin of every single sinner who believes in Him. Then He rose again on the 3rd day to prove that He is God and that His cross has power to save. This faith in Jesus is not mere intellectual assent but the kind of trust that binds and unites the believer to Christ spiritually. “If you confess with your mouth: Jesus is LORD [God], and believe in your heart that God raised Him from the dead, you will be saved” (Romans 10:9).
Genuine faith in Jesus is accompanied by repentance of sin, turning away from sin toward submission under the authority of Jesus and the Word of God. “If we confess our sins, God is faithful and just to forgive us our sins and cleanse us from all unrighteousness” (1 John 1:9) When faith is put in Jesus, God gives the gift of the Holy Spirit to indwell the believer to live a holy life.
The outward sign and seal of true saving faith and repentance is baptism, where you make a public declaration of faith in Christ by symbolically dying to yourself (going under the water) to rise with Him to new life. The Christian ought to grow in the daily spiritual disciplines of personal Bible study and prayer, and he or she should join themselves to a local Bible-teaching church to serve and to grow in Christ through learning Scripture under faithful preaching, partaking in the Lord’s Supper, joining in fellowship and corporate prayer (see Acts 2:42), waiting for the glorious return of the Lord Jesus Christ.