"Everyone who sins breaks the law; in fact, sin is lawlessness." I John 3:4, NIV.
"All wrongdoing is sin" I John 5:17, NIV
What is God's law? He wrote it with His own finger in tables of stone. " You shall have no other gods before Me.  You shall not make for yourself an idol in the form of anything in heaven above or on the earth beneath or in the waters below. You shall not bow down to them or worship them; for I, the Lord your God, am a jealous God, punishing the children for the sin of the fathers to the third and fourth generation of those who hate Me, but showing love to thousands who love Me and keep My commandments.  You shall not misuse the name of the Lord your God, for the Lord will not hold anyone guiltless who misuses His name.  Remember the Sabbath day by keeping it holy. Six days you shall labor and do all your work, but the seventh day is a Sabbath to the Lord your God. On it you shall not do any work, neither you, nor your son or daughter, nor your manservant or maidservant, nor your animals, nor the alien within your gates. For in six days the Lord made the heavens and the earth, the sea, and all that is in them, but He rested on the seventh day. Therefore the Lord blessed the Sabbath day and made it holy.  Honor your father and your mother, so that you may live long in the land the Lord your God is giving you.  You shall not murder.  You shall not commit adultery.  You shall not steal.  You shall not give false testimony against your neighbor.  You shall not covet your neighbor's house. You shall not covet your neighbor's wife, or his manservant or maidservant, his ox or donkey, or anything that belongs to your neighbor." Exodus 20:3-17, NIV.
The basic principal of God's law is summed up in one wordólove. "Jesus replied: 'Love the Lord your God with all your heart and with all your soul and with all your mind. This is the first and greatest commandment. And the second is like it: 'Love your neighbor as yourself.' All the Law and the Prophets hang on these two commandments."
Matthew 22:37-40, NIV.
Sin comes from the inside out. "And then He added, 'It is the thought-life that pollutes. For from within, out of men's hearts, come evil thoughts of lust, theft, murder, adultery, wanting what belongs to others, wickedness, deceit, lewdness, envy, slander, pride, and all other folly. All these vile things come from within; they are what pollute you and make you unfit for God."
Mark 7:20-23, TLB.
No one is better than anotherówe all sin. "Well, then, are we Jews better than others? No, not at all, for we have already shown that all men alike are sinners, whether Jews or Gentiles. As the Scriptures say, 'No one is goodóno one in all the world is innocent.'"
Romans 3:9-10, TLB.
Without Jesus, the consequences of our sin is death. "For the wages of sin is death, but the free gift of God is eternal life through Jesus Christ our Lord."
Romans 6:23, TLB.
What if I'm not sure of what all my sins are? "Search me, O God, and know my heart; test my thoughts. Point out anything you find in me that makes You sad, and lead me along the path of everlasting life." Psalm 139:23-24, TLB.
Confess sin to God and receive forgiveness. "If we confess our sins, He is faithful and just and will forgive us our sins and purify us from all unrighteousness."
I John 1:9, NIV.
Is any sin unforgivable? "And everyone who speaks a word against the Son of Man will be forgiven, but anyone who blasphemes against the Holy Spirit will not be forgiven." Luke 12:10, NIV.
To symbolize turning away from sin we should be baptized. "Then John went from place to place on both sides of the Jordan River, preaching that people should be baptized to show that they had turned to God and away from their sins, in order to be forgiven."
Luke 3:3, TLB.
If you feel like a hopeless sinner, what should you do? First acknowledge your sin. "Oh, wash me, cleanse me from this guilt. Let me be pure again. For I admit my shameful deedóit haunts me day and night." Psalm 51:2-4, TLB.
Second, Ask forgiveness for your sin. "Sprinkle me with the cleansing blood and I shall be clean again. Wash me and I shall be whiter than snow. And after You have punished me, give me back my joy again. Don't keep looking at my sinsóerase them from Your sight. Create in me a new, clean heart, O God, filled with clean thoughts and right desires. Don't toss me aside, banished forever from Your presence. Don't take Your Holy Spirit from me. Restore to me again the joy of Your salvation, and make me willing to obey You." Psalm 51:7-12, TLB.
Third, Believe that God has indeed forgiven you and quit feeling guilty. "What happiness for those whose guilt has been forgiven! What joys when sins are covered over! What relief for those who have confessed their sins and God has cleared their record. There was a time when I wouldn't admit what a sinner I was. But my dishonesty made me miserable and filled my days with frustration. All day and all night Your hand was heavy on me. My strength evaporated like water on a sunny day until I finally admitted all my sins to You and stopped trying to hide them. I said to myself, 'I will confess them to the Lord.' And You forgave me! All my guilt is gone. Now I say that each believer should confess his sins to God when he is aware of them, while there is time to be forgiven. Judgment will not touch him if he does. You are my hiding place from every storm of life; You even keep me from getting into trouble! You surround me with songs of victory." Psalm 32:1-6, TLB.5