A genuine believer will know that he/she can never abuse the grace of God and His forgiveness and think that they have a license to sin. A believer might sin occasionally (in which forgiveness is available from God when you genuninely repent), however, there is a huge difference between sinning occasionally and sinning continuously with the mindset of being ok in abusing God's grace. For example, lustful thoughts come inevitably in an evil world which glorifies extramarital sex and even idolizes sex altogether as if it needs to be a mandatory achievement in this life (we're surrounded by people who are obsessed with sex, materialism/wealth, etc.). Sex is not evil as long as it is confined to marriage.
When lustful desires come to your mind, do you sin in your mind (by fantasizing) or even take it further by going to strip clubs, watching porn, having casual sex, etc.? All of those things are wrong (fornication/adultery in the heart/mind as well as engaging in the real thing). Again anyone who thinks that such things are ok as long as you ask God for forgiveness each time has the wrong mentality of grace. Just because forgiveness is available for occassional sin, that doesn't give you the license to go take advantage of that also. I think this is what many Christians practice in regards to sex outside of marriage or any other type of sin- take advantage of forgiveness and grace. For example, if someone is a virgin, and then they take advantage of occassional sin's forgiveness and grace by doing some things or everything available out there at least once (go to strip clubs, have casual sex, etc.) before getting married- thinking that they will be easily forgiven, do they think the Bible condones that? That is abusing God's grace. Deliberate sin like that is not condoned by the Bible. Instead, warnings are given regards to that in the Bible. If anyone has done that in the past, now is the time to repent and not continue abusing God's grace.
If you got caught by a policeman for speeding and you got off with a warning, do you continue to break the law by speeding thinking that the same policeman will be gracious to you each time? No. If you do, you'd find out quickly how foolish that would be and how you could find yourself in court with bigger consequences. People treat (abuse) God's goodness and grace in the same way to think that they will get away with breaking His law everytime. False teachers have instilled such an abusive/sociopathic mindset into many Christians- a trap which many Christians are finding difficulty to get free from (as they find themselves enslaved to sin). False teachers alter the normal psychology of people through brainwashing and deception. They love to sugar coat sin. Look how Satan deceived Eve to think that no harm would come to her by disobeying God. How did that turn out? A complete disaster for her and the rest of mankind. In a spiritual sense, I think Satan was able to get his own sociopathic human race on earth by deceiving the first parents in the Garden of Eden. By causing the seed of sin (an evil virus) to enter all of creation, mankind were born in sin and thus children of darkness even though God Himself created each of us in the womb. As Satan was successful in stealing away God's creation from Him, God had a plan for redemption to get His creation back through Jesus Christ (the good seed). So anyone who accepts Jesus Christ (the good seed), becomes spiritually transformed (becoming transformed from spiritual darkness and instead into spiritual Light) to become like Christ in character and in the future, we'll get a transformed body like His which will be glorious. God has a plan to bring glory to us if we would simply lay down our arms (our sin and rebellion against Him). That is a challenging thing to do in a world which is at war with us for control of our minds- to make us continue in sin for it's temporary pleasure. It deceives us by making us think that eternal glory which we can't see right now is not worth what you get right now through sin on earth. It deceives us to forget that the happiness from things on earth is temporary, we won't take anything which make us happy into eternity. How many people have taken their achievements and possessions into the grave and beyond? None. In the grave, you get a sheet of maggots eating away at your body for the penalty of sin and your soul will either be in Hades or in Paradise depending on whether or not you obtained salvation through Christ.
The key to overcoming sin is to assess what/who is the center of your focus? God or sinful desires? The mind is in a constant struggle to keep God always in the center, but that's how every battle with temptation is won. When sin is at the center of your focus, replace it with God. When God is at the center of your focus and sinful desires try to entice you to replace God with sin at the center, you have to deny sin from replacing God, no matter how hard (tempting) it is.
An abusive mindset (especially abusing God's grace) is characteristic of a sociopath ("children of the devil" according to 1 John 3).
1 John 3:1-10 (NLT):
"See how very much our Father loves us, for he calls us his children, and that is what we are! But the people who belong to this world don’t recognize that we are God’s children because they don’t know him. 2 Dear friends, we are already God’s children, but he has not yet shown us what we will be like when Christ appears. But we do know that we will be like him, for we will see him as he really is. 3 And all who have this eager expectation will keep themselves pure, just as he is pure.
4 Everyone who sins is breaking God’s law, for all sin is contrary to the law of God. 5 And you know that Jesus came to take away our sins, and there is no sin in him. 6 Anyone who continues to live in him will not sin. But anyone who keeps on sinning does not know him or understand who he is.
7 Dear children, don’t let anyone deceive you about this: When people do what is right, it shows that they are righteous, even as Christ is righteous. 8 But when people keep on sinning, it shows that they belong to the devil, who has been sinning since the beginning. But the Son of God came to destroy the works of the devil. 9 Those who have been born into God’s family do not make a practice of sinning, because God’s life is in them. So they can’t keep on sinning, because they are children of God. 10 So now we can tell who are children of God and who are children of the devil. Anyone who does not live righteously and does not love other believers does not belong to God."
Hebrews 10:26-31 (NLT):
"Dear friends, if we deliberately continue sinning after we have received knowledge of the truth, there is no longer any sacrifice that will cover these sins. 27 There is only the terrible expectation of God’s judgment and the raging fire that will consume his enemies. 28 For anyone who refused to obey the law of Moses was put to death without mercy on the testimony of two or three witnesses. 29 Just think how much worse the punishment will be for those who have trampled on the Son of God, and have treated the blood of the covenant, which made us holy, as if it were common and unholy, and have insulted and disdained the Holy Spirit who brings God’s mercy to us. 30 For we know the one who said,
“I will take revenge.
I will pay them back.”
He also said,
“The Lord will judge his own people.”
31 It is a terrible thing to fall into the hands of the living God."
Jude 1:4 (NLT):
"I say this because some ungodly people have wormed their way into your churches, saying that God’s marvelous grace allows us to live immoral lives. The condemnation of such people was recorded long ago, for they have denied our only Master and Lord, Jesus Christ."