Great question. God's laws are laws of love. If we live by God's government of love and righteouness we are fitted for Heaven. "Therefore all things whatsoever ye would that men should do to you, do ye even so to them: for this is the law and the prophets." Matthew 7:12.

God gave us the Bible so we can know the truth and learn God's requirements. As the word is spread by His messengers, people have the opportunity to choose to become God's children and go to Heaven or Satan's slave be destroyed with him. "And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come." Mat 24:14

"But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name:" John 1:12 "... Sirs, what must I do to be saved? And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house." Act 16:30-31

The sinner you talk of goes to heaven because he repented of his sins and God forgave him. "But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us." Romans 5:8. "For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord." Romans 6:23

"The kingdom of heaven is like unto a certain king, which made a marriage for his son, and sent forth his servants to call them that were bidden to the wedding: and they would not come.

"Again, he sent forth other servants, saying, Tell them which are bidden, Behold, I have prepared my dinner: my oxen and my fatlings are killed, and all things are ready: come unto the marriage. But they made light of it, and went their ways, one to his farm, another to his merchandise:

"And the remnant took his servants, and entreated them spitefully, and slew them.

"But when the king heard thereof, he was wroth: and he sent forth his armies, and destroyed those murderers, and burned up their city.

"Then saith he to his servants, The wedding is ready, but they which were bidden were not worthy. Go ye therefore into the highways, and as many as ye shall find, bid to the marriage.

"So those servants went out into the highways, and gathered together all as many as they found, both bad and good: and the wedding was furnished with guests.

"And when the king came in to see the guests, he saw there a man which had not on a wedding garment:

"And he saith unto him, Friend, how camest thou in hither not having a wedding garment? And he was speechless.

"Then said the king to the servants, Bind him hand and foot, and take him away, and cast him into outer darkness, there shall be weeping and gnashing of teeth. For many are called, but few are chosen." Matthew 22:2-14

"Therefore is the kingdom of heaven likened unto a certain king, which would take account of his servants.

"And when he had begun to reckon, one was brought unto him, which owed him ten thousand talents. But forasmuch as he had not to pay, his lord commanded him to be sold, and his wife, and children, and all that he had, and payment to be made.

"The servant therefore fell down, and worshipped him, saying, Lord, have patience with me, and I will pay thee all.

"Then the lord of that servant was moved with compassion, and loosed him, and forgave him the debt.

"But the same servant went out, and found one of his fellowservants, which owed him an hundred pence: and he laid hands on him, and took him by the throat, saying, Pay me that thou owest.

"And his fellowservant fell down at his feet, and besought him, saying, Have patience with me, and I will pay thee all.

"And he would not: but went and cast him into prison, till he should pay the debt.

"So when his fellowservants saw what was done, they were very sorry, and came and told unto their lord all that was done.

"Then his lord, after that he had called him, said unto him, O thou wicked servant, I forgave thee all that debt, because thou desiredst me: Shouldest not thou also have had compassion on thy fellowservant, even as I had pity on thee?

"And his lord was wroth, and delivered him to the tormentors, till he should pay all that was due unto him.

"So likewise shall my heavenly Father do also unto you, if ye from your hearts forgive not every one his brother their trespasses." Matthew 18:23-35