I would like to know if God will forgive me if I sin? What if I asked for His forgiveness, but there are times that I am still doing the bad things, such as sleeping with my fiance though we are not yet married? There are times I realize that I have done something wrong in the sight of God. Will God still forgive me for being hard-headed sometimes? What should I do?
Better than anyone, God understands that sin is not good for people. Though it appears to be fun and exciting on the surface, the ultimate consequence of sin is pain and misery. "The Lord is not slack concerning His promise, as some count slackness, but is longsuffering toward us, not willing that any should perish but that all should come to repentance" (II Peter 3:9). Thus God's goal is to rescue as many people as He can from ourselves and our sins.
The key though is that the person must change; that is what repentance means. Imagine trying to rescue someone who is drowning, but who at the same time refuses to get out of the water. The same problem occurs when God tries to save a person from sin, but he remains in it. ""But if a wicked man turns from all his sins which he has committed, keeps all My statutes, and does what is lawful and right, he shall surely live; he shall not die. None of the transgressions which he has committed shall be remembered against him; because of the righteousness which he has done, he shall live. Do I have any pleasure at all that the wicked should die?" says the Lord GOD, "and not that he should turn from his ways and live?"" (Ezekiel 18:21-23).
Therefore, the answer is, of course, God is willing and able to forgive you of your sins, but you have to leave them. You can't be committing fornication and expect God to accept you as you are. ""Therefore I will judge you, O house of Israel, every one according to his ways," says the Lord GOD. "Repent, and turn from all your transgressions, so that iniquity will not be your ruin. Cast away from you all the transgressions which you have committed, and get yourselves a new heart and a new spirit. For why should you die, O house of Israel? For I have no pleasure in the death of one who dies," says the Lord GOD. "Therefore turn and live!"" (Ezekiel 18:30-32).