What is sin? It is the breaking of God's law. It's in the Bible, I John 3:4, CEV. "Everyone who sins breaks God's law, because sin is the same as breaking God's law. "
It's in the Bible, I John 5:17, NIV. "All wrongdoing is sin…..."
What is God's law? The Ten Commandments, He wrote it with His own finger in tables of stone. It's in the Bible, Exodus 20:3-17, NKJV.
 “You shall have no other gods before Me.
“You shall not make for yourself a carved image—any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them nor serve them. For I, the LORD your God, am a jealous God, visiting the iniquity of the fathers upon the children to the third and fourth generations of those who hate Me, but showing mercy to thousands, to those who love Me and keep My commandments.
“You shall not take the name of the LORD your God in vain, for the LORD will not hold him guiltless who takes His name in vain.
“ Remember the Sabbath day, to keep it holy. Six days you shall labor and do all your work, but the seventh day is the Sabbath of the LORD your God. In it you shall do no work: you, nor your son, nor your daughter, nor your male servant, nor your female servant, nor your cattle, nor your stranger who is within your gates. For in six days the LORD made the heavens and the earth, the sea, and all that is in them, and rested the seventh day. Therefore the LORD blessed the Sabbath day and hallowed it.
“Honor your father and your mother, that your days may be long upon the land which the LORD your God is giving you.
“You shall not murder.
“You shall not commit adultery.
“You shall not bear false witness against your neighbor.
“You shall not covet your neighbor’s house; you shall not covet your neighbor’s wife, nor his male servant, nor his female servant, nor his ox, nor his donkey, nor anything that is your neighbor’s.”
The basic principal of God's law is summed up in one word—love. It's in the Bible, Matthew 22:37-40, NIV. "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."
Sin comes from within - from the sinful desires of our hearts. It's in the Bible, Mark 7:20-23, TLB. "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."
We are all sinners; we have all sinned. It's in the Bible, Romans 3:10, NKJV. "As it is written, 'There is none righteous, no, not one'"
It's in the Bible, Romans 3:23, "For all have sinned, and come short of the glory of God"
The penalty for sin is death. It's in the Bible, Romans 6:23, NKJV. "For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord."
God the Son, came to our world to save us. It's in the Bible, Matthew 1:21, NKJV. " And she will bring forth a Son, and you shall call His name JESUS, for He will save His people from their sins.”
How does Jesus save us from sin? Jesus paid the penalty for our sins, and gives us His perfect righteousness. It's in the Bible, 2 Corinthians 5:21, NKJV. "For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him."
Does God hate sinners? No, Christ died for us even though we are sinners. It's in the Bible, Romans 5:8, NKJV. "But God demonstrates His own love toward us, in that while we were still sinners, Christ died for us.
If we confess our sins to God and ask Him to forgive us, He will do so. It's in the Bible, I John 1:9, NKJV. "If we confess our sins, He is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness."
What if I'm not sure of what all my sins are? It's in the Bible, Psalm 139:23-24, NKJV. " Search me, O God, and know my heart; try me, and know my anxieties; and see if there is any wicked way in me, and lead me in the way everlasting."
Is there any sin God cannot forgive? It's in the Bible, Matthew 12:31-32, NKJV. "Therefore I say to you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men. Anyone who speaks a word against the Son of Man, it will be forgiven him; but whoever speaks against the Holy Spirit, it will not be forgiven him, either in this age or in the age to come."
Note: The only sin that cannot be forgiven is the sin for which we do not repent and ask forgiveness. Sinning against the Holy Spirit cannot be forgiven, because it is the Holy Spirit who convicts us of sin, and if we resist Him and refuse to listen to Him, we are making it impossible for Him to convict us of sin and lead us to Jesus for forgiveness.
Baptism is a symbol of the fact that we are turning away from sin and trusting Jesus for a new life of victory over sin. It's in the Bible, Luke 3:3, TLB. "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."
If you feel like a hopeless sinner, what should you do?
First acknowledge your sin. It's in the Bible, Psalm 51:2-3, NKJV. "Wash me thoroughly from my iniquity, and cleanse me from my sin. For I acknowledge my transgressions, and my sin is always before me."
Second, ask forgiveness for your sin. It's in the Bible, Psalm 51:7-12, NKJV. " Purge me with hyssop, and I shall be clean; Wash me, and I shall be whiter than snow. Make me hear joy and gladness, that the bones You have broken may rejoice. Hide Your face from my sins, and blot out all my iniquities. Create in me a clean heart, O God, and renew a steadfast spirit within me. Do not cast me away from Your presence, and do not take Your Holy Spirit from me. Restore to me the joy of Your salvation, and uphold me by Your generous Spirit."
Third, believe that God has indeed forgiven you - and quit feeling guilty. It's in the Bible, Psalm 32:1-5, NKJV. "Blessed is he whose transgression is forgiven, whose sin is covered. Blessed is the man to whom the LORD does not impute iniquity, and in whose spirit there is no deceit. When I kept silent, my bones grew old through my groaning all the day long. For day and night Your hand was heavy upon me; my vitality was turned into the drought of summer. I acknowledged my sin to You, and my iniquity I have not hidden. I said, “I will confess my transgressions to the LORD,” and You forgave the iniquity of my sin."