Source: Johan Paulin, Real Humans, io9
As I am not a believer in Augustinian original sin,
I feel obliged to explain this question I received a lot:
“If you do not believe in original sin, then how come every human being* up until this point has sinned?”
My view on why all people sin is:
“When the sentence for a crime is not quickly carried out,
people’s hearts are filled with schemes to do wrong.”
– Ecclesiastes 8:11 (NIV)
“You were rescued from the useless way of life that you LEARNED FROM [NOT inherited from] your ancestors. But you know that you were not rescued by such things as silver or gold that don’t last forever. You were rescued by the precious blood of Christ, that spotless and innocent lamb.”
– 1 Peter 1:18-19 (CEV, emphasis mine, added “[NOT inherited from]”)
(Notice the calvinist ESV corruption to get the word “inheritance” in there.
Notice also that this verse shows, to a certain extent, that Pelagius was right.)
“Therefore, just as sin entered the world through one man, and death through sin, in this way death spread to all men, because all sinned”
– Romans 5:12 (HCSB)
Because people, since the fall of Adam and Eve, saw that others broke God’s law** and were not instantly judged***, they imitated other sinners
and, in that way, became sinners themselves.
If you see all the sinning** around you… and you do not see instant punishment***… and you need to resist 100000000000000000000000000000000000000000000000000 possibilities of sinning in your life… God knew that you would have 99.9999999999999999999999999999999999999999999999999999999999% chance to sin,
which makes it 100% (rounded).
(Pelagius did not believe that we can be saved by our own good deeds. In fact, he proclaimed many times, in his commentary on the Letter to the Romans that it is Christ’s righteousness – and not our own righteousness – that saves us. Augustine clearly misrepresented him.)
In His love, God knew He had to send the Saviour to die only to save those who had sinned, those who would perish in the Lake of Fire.
‘And when the scribes and Pharisees saw Him eating with publicans
and sinners, they said unto His disciples,
“How is it that he eateth and drinketh with publicans and sinners?”
When Jesus heard it, He said unto them,
“They that are whole have no need of the physician, but they that are sick.
I CAME NOT TO CALL THE RIGHTEOUS, BUT SINNERS TO REPENTANCE.”’
– Mark 2:16-17 (KJ21, emphasis mine)
“For the wages of sin is death;
but the gift of God is eternal life
through Jesus Christ our Lord.”
– Romans 6:23 (KJV)
“God proves His own love for us
in that while we were still sinners,
Christ died for us!”
– Romans 5:8 (HCSB)
“For God made Christ, who never sinned, to be the offering for our sin,
so that we could be made right with God through Christ.”
– 2 Corinthians 5:21 (NLT)
God did NOT give us a sinful nature. He is not to be blamed for the sins we commit: https://crosstheology.wordpress.com/sinful-nature/
* I must point out that the (God-)Man Jesus Christ never sinned, as seen in the previous verse.
It is possible that Noah, Job and Daniel were sinless [Genesis 6:9, Ezekiel 14:14: “and these three men have been in its midst, Noah, Daniel, and Job — they by their righteousness deliver their own soul — an affirmation of the Lord Jehovah.” (YLT)]. It is also possible that Enoch never sinned [Genesis 5:22-24, Hebrews 11:5, Ezekiel 18:4b: “The soul who sins will die” (NASB) + Ezekiel 18:9: ‘“if he walks in My statutes and My ordinances so as to deal faithfully—he is righteous and will surely live,” declares the Lord God.’ (NASB)] but that is not entirely clear for it is possible that Enoch repented after he begat his son Methuselah (Genesis 5:22). Then Ezekiel 18:21 ‘took place’: “But if the wicked man turns from all his sins which he has committed and observes all My statutes and practices justice and righteousness, he shall surely live; he shall not die.” (NASB). [For the idea that not everyone sinned, in light of Romans 3, click here. For the contrary idea: that everyone, except for Jesus, sinned, click here to get to know why there is no necessity of a sinful nature for a universal development of sinfulness.]
If you fulfil the whole law [1 John 3:4; Mark 12:30-31], no forgiveness is required. If you do it from birth, no one could accuse you in order that you would be rejected to enter into the Heavenly City [Hebrews 11:16; Hebrews 13:4; Revelation 21:2] “Blessed are they that do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city.” [Quoted: Revelation 22:14 (KJV)]. It seems to me that it is possible. It should be noted that even if someone would do it that way, it is still by grace through faith on various reasons: 1) He did not deserve to be illuminated by the light that enlightens every man that comes into the world (John 1:9) 2) He did not deserve to have God’s Laws written on the tablet of his heart (Romans 2:14-16) 3) Another reason why he is still saved in the way of Ephesians 2:8-9 (NIV): “by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God— not by works, so that no one can boast.” is that in the end, he still has no rights to demand for God having to take him into his kingdom. This is all by grace as in the verse that has just been quoted. Some people have brought 1 John 1:8,10 “If we claim to be without sin, we deceive ourselves and the truth is not in us. If we claim we have not sinned, we make him out to be a liar and his word is not in us.” against this personal conclusion but that verse is written against the gnostics, who believed they had no sin because they thought the human spirits were good, while their bodies were inevitably evil. They believed that that the human body (flesh) caused you to sin inevitably and that therefore you were not guilty of those sins and so you “had no sin”. Others have used Romans 3:23 “for all have sinned and fall short of the glory of God” to say that all human beings must sin. But in context, this verse is based on a verse “All have turned away, they have together become worthless; there is no one who does good, not even one.” (Romans 3:12) which is a poetic exaggeration by king David, just like Psalm 51:5 is. Furthermore, I see not one single verse in the Bible that states that we are born with a sin nature, that makes our sin which we commit inevitable (as the gnostics thought). Furthermore, as just one example, Jesus commanded us to “Be perfect, therefore, as your heavenly Father is perfect.” (Matthew 5:48), according to Him, the most important commandment was to “Love the Lord your God with all your heart and with all your soul and with all your strength and with all your mind” (Matthew 22:37), which was once followed by a beautiful promise of Jesus “Do this and you will live.” (Luke 10:28b). Therefore I conclude that not sinning is not an impossibility (contrary to what the gnostics thought). Not sinning ones entire life is possible but it demands that one “blocks/dodges” all attacks/deceptions of influences by others.
Archelaeus, in his discussion with Mani the gnostic, is recorded to have said: “The example of his [satan’s] fall and ruin, however, will not be followed by all, inasmuch as to each is given liberty of will” – Archelaeus, The Acts of the Disputation With Manes, 32.
 It was so important to Jesus that He even concluded with the words:
“All the Law and the Prophets hang on these two commandments” (Matthew 22:40).
 “And the second is like it: ‘Love your neighbor as yourself.’” (Matthew 22:39)
[Part taken from my upcoming commentary on the Epistle of Paul to The Galatains (Check “The Store” for more information.]
** “sin is the transgression of the law [of God]” – 1 John 3:4b (KJV, added words between brackets)
*** Reason: “The Lord is being patient toward you, because he does not wish for any to perish but for all to come to repentance” – 2 peter 3:9b (NET) Read also Psalm 145:8-9: “The LORD is gracious, and full of compassion; slow to anger, and of great mercy. The LORD is good to all: and his tender mercies are over all his works.” – Psalm 145:8-9 (KJV) [Those Calvinists who believe that God only wants to save some, should read 1 Timothy 2:4-6, right after they have read 2 Peter 3:9. They should also read “Against “The Hidden Will” of The Father”]