Years ago, I was told that sin is "an offense against God". That seemed pretty simple and straight forward to me, but now and then I have heard people speak of sin as an offense against other people. So I'm wondering if they are mistaken about the nature of sin, or if sin is both an offense against God and other people, or what? That is, is sin an offense against someone, and if so, who? And more broadly, what is sin?
This question is mainly for Abrahamics, of course, but anyone can offer their views.
God's plan, as He gradually reveals to humans, is to build an eternity we call Heaven for His creatures such as the angels and humans living with Him forever. However God hates something which we call sin. God is said to be completely sin incompatible. Law is thus set up to address what a sin is, so that if any entities with freewill chooses to break the Law in a specified period of time then he's disqualified to enter the final Heaven. That's why there's a Final Judgment to legitimately and openly bring those qualified to Heaven. That's when the New Heaven and New earth starts to run.
However under the influence of Satan, the first lineage of humans sinned when put in Eden (a place inside God's realm). Since then humans are driven out of God's realm, living in the current planet earth where Satan is literally said to be the god of this world. When humans are no longer inside God's realm, with Satan's influence being much stronger, no human can thus enter the final heaven by abiding the Law. This point is proven (by God) so it came the story of Noah. God's purpose for humans (to live the eternal Heaven) was defeated. Humans as a whole will fail the final judgment of God's Law. Thus the existence of earth serves no purpose but a pool of sins which God hates. It's thus time to destroy this pool of sins once and for all (by water).
Satan thus triumphs as he has destroyed God's plan of bringing humans to Heaven. But it's not yet. God has Jesus Christ the savior. Through the blood of Jesus Christ God can now grant a series of covenants as a mean of salvation to humans. A covenant simply says, "since you humans can't abide by God's Law in full, you only need to abide by a set-aside set of rules (such as Mosaic Law) to a said standard, such that you will be saved by God's Grace through Jesus Christ. Each and every covenant serves the main purpose of identifying and thus separating the righteous from the wicked. The righteous thus will be brought to Heaven legitimately under open witnessing (of angels and saints).
Satan (and his angels) on the other hand will stress his influence, humans will thus sin further to an extent that an older covenant may fail in identifying the righteous (the harvest). Then it is time for God to upgrade His covenant to a newer one by granting more Grace, such that His Elect (the righteous) will become savable.
Romans 5:20-21 (NIV2011)
20 The law was brought in so that the trespass might increase. But where sin increased, grace increased all the more,
21 so that, just as sin reigned in death, so also grace might reign through righteousness to bring eternal life through Jesus Christ our Lord.
The New Covenant brought in directly by Jesus Himself became the final covenant because it has the maximum Grace granted. Under this covenant, our salvation is measured by our faith alone. Faith in Christ becomes the only rule (unlike Mosaic Law) applied for us to be saved. You believe with Faith in a correct fashion then you will be saved (brought to the final Heaven) legitimately and openly.
Whether one can fulfill what a covenant said will be judged by Jesus Christ Himself, because all the Grace is granted under His name. His blood gives Him the right to grant the Grace to anyone He wishes though He will judge fairly and He will judge what is deep inside your heart. The angels and saints will also be the witnesses to see if you have fulfilled the covenant. As for the New Covenant, Jesus will judge if your faith qualifies you to enter the final Heaven.
If you are considered (by Jesus Christ) to fail the covenant, then you will be judged by the Law which will sentence you to death (the second death) with whatever consequences it brings.