The study of sin is hamartiology. Sin is described as in the bible as a transgression of the law of God, in 1 John 1 :4 - Whoever commits sin also commits lawlessness, and sin is lawless. It is rebellion against God, read (Deuteronomy 9:7), (Joshua 1:18). We see a story when Satan tempted Eve to eat this fruit so she can become her own god, and when she ate it, she gave it to Adam, and he did eat also. They were both naked and hid from God, we know that God knows everything because he is omniscient. When God found out he punish Adam, Eve and Satan he put curses on them, you can also read full story out of Genesis 3. We know that sin is deadly because Paul said in Romans 6:23 - For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord. Sin had its beginning with Lucifer when he wants to be higher than God, Lucifer had pride in him. The Pride took lucifer down, read (Isaiah 14:12-15). Sin entered into the world by one man (Adam), Romans 5:12 - Therefore, just as through one man sin entered the world, and death through sin, and thus death spread to all men, because all sinned.  God had to send spotless Lamb Jesus Christ to pay the price for our sins, Jesus had to die for everyone, in 1 John 2:2 - And he himself is the propitiation for our sins, and not ours only but also for the whole world. Jesus was the final sacrifice for us, read (Hebrews 10). We know this verse in John 3:16 - For God so loved the world. that he gave his only begotten Son, that whoever believes in Him should not perish but have everlasting life. We will talk about Soteriology.