"Good News" is what "Gospel" literally means. The Good News is defined this way in the Bible:
1 Corinthians 15:1-4 Now I made known to you, brothers, the Gospel which I preached to you, which also you received, in which you also stand, through 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 was raised on the third day according to the Scriptures.
The Good News of Jesus is essentially three facts: 1) Christ's death for His people's sins; 2) His burial; 3) His Resurrection.
Why is this particularly Good News? Because the sin Jesus died for would have sent us to Hell:
Revelation 21:8 But the cowardly, and unbelieving, and sinners, and abominable, and murderers, and fornicators, and drug users, and idolaters, and all who are false shall have their part in the lake which burns with fire and brimstone, which is the Second Death."
For most people, Jesus' death is not Good News, because they don't think they have sinned, or they don't think their sin is bad enough to send them to Hell. Therefore, the Good News in only Good News to those who believe the Bad News about their sinfulness.
1 John 1:8 If we claim that we have no sin, we are deceiving ourselves, and the truth is not in us.
1 John 1:10 If we claim that we have not sinned, we make Him a liar, and His word is not in us.
Christians remain humble people, because they know what they deserved. (One sign of a fake Christian is lack of this humility.) Look at the two verses above. Notice a missing verse between 8 and 10?
1 John 1:9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
"Confess" literally means "Say the same." When we confess our sins, we say the same thing about them that God does. God says sin is worthy of Hell: we agree. God says sin destroys us and others: we agree again. AND we agree with our own particular deeds, thoughts, and attitudes that God defines as sinful.
If we really agree, then, about our sin, will we keep purposely sinning? No:
Proverbs 28:13 He who covers his sins shall not be blessed; but whoever confesses and leaves them shall have mercy.
Leaving our sins is called repentance.
But does repentance get rid of sinful desires? No. God gives us a new heart and spirit that desire good, but, for now, He leaves "the old man" within us to teach us spiritual combat. Of the new heart:
Ezekiel 36:26-27 And I will give you a new heart, and I will put a new spirit within you. And I will take away the stony heart out of your flesh, and I will give you a heart of flesh. And I will put My Spirit within you and cause you to walk in My statutes, and you shall keep My judgments and do them.
God implants a new heart- one that desires God and good, but the "old man" stays with us for now:
Ephesians 4:22-24 For you ought to put off the old man (according to your way of living before) who is corrupt according to the deceitful lusts, and be renewed in the spirit of your mind. And you should put on the new man, who according to God was created in righteousness and true holiness.
It is a battle. The "flesh" is another name for the old man.
Gal 5:17 For the flesh desires against the Spirit, and the Spirit against the flesh; and these things oppose each other, so that you do not do the things that you wish.
Christians are fighting against a strong, constant headwind- within ourselves!- not to mention the pressures and seductions from without. Jesus never tried to fool anyone (though many who claim to speak in His name do). He told us up front what is involved in following Him:
Luke 13:23-24 Then one said to Him, "Lord, are there few who are saved?" And He said to them, Strive to enter through the narrow gate, because many, I say to you, will seek to enter and will not be able.
God's generosity and presence to help are always near. We just get tired, distracted, and confused. We stop believing God really cares, so we stop reaching out to Him. If you trust in Christ to cleanse and renew you, you are taking the first step of a journey that ends joyously in His presence. You can only take the journey day by day. You already know on your first day that there will be hard days- maybe many of them, maybe most. But your are putting your confidence in Jesus to see you through.
Revelation 1:7-8 Behold, He is coming with the clouds, and every eye will see Him, and those who pierced Him. And all the tribes of the earth will wail because of Him. Even so, Amen!. "I am the Alpha and the Omega," says the Lord God, "He who is and He who was and He who is to come, The Almighty."