What is idolatry?
Romans 1:21 and 25
For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened…. They exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator.
What is sin?
1 John 3:4
Everyone who makes a practice of sinning also practices lawlessness; sin is lawlessness.
1 Peter 2:24
He himself bore our sins in his body on the tree, that we might die to sin and live to righteousness. By his wounds you have been healed.
Who his own self bare our sins This form of speaking is fitted to set forth the efficacy of Christ’s death. For as under the Law, the sinner, that he might be released from guilt, substituted a victim in his own place; so Christ took on himself the curse due to our sins, that he might atone for them before God. And he expressly adds, on the tree, because he could not offer such an expiation except on the cross. Peter, therefore, well expresses the truth, that Christ’s death was a sacrifice for the expiation of our sins; for being fixed to the cross and offering himself a victim for us, he took on himself our sin and our punishment. Isaiah, from whom Peter has taken the substance of his doctrine, employs various forms of expression, — that he was smitten by God’s hand for our sins, that he was wounded for our iniquities, that he was afflicted and broken for our sake, that the chastisement of our peace was laid on him. But Peter intended to set forth the same thing by the words of this verse, even that we are reconciled to God on this condition, because Christ made himself before his tribunal a surety and as one guilty for us, that he might suffer the punishment due to us.~John Calvin Commentary
Lest, however, we should think that the patience of our Lord was intended to be our example and nothing more, the apostle goes on to speak expressly of the expiatory nature of the sufferings alluded to. He has held up the Savior in all His woes as our example, but knowing the evil tendency of skeptical minds, by any means, to becloud the cross, he now puts aside the example, for a moment, and speaks of the Redeemer as the great sacrifice for sin. The sacred writers are always very clear and distinct upon this truth and so must we be. There is no preaching the gospel if the atonement is left out. No matter how well we speak of Jesus as a pattern, we have done nothing unless we point Him out as the substitute and sin-bearer. We must, in fact, continually imitate the apostle, and speak plainly of Him, “Who His own self bore our sins in His own body on the tree.”~Charles Spurgeon
Since no one can keep the law, what is its purpose?
For by works of the law no human being will be justified in God’s sight, since through the law comes knowledge of sin.
Did God create us unable to keep his law?
Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned.
Can anyone keep the law of God perfectly?
None is righteous, no, not one; no one understands; no one seeks for God. All have turned aside; together they have become worthless; no one does good, not even one.
What does God require in the sixth, seventh, and eighth commandments?
For the commandments, “You shall not commit adultery, You shall not murder, You shall not steal, You shall not covet,” and any other commandment, are summed up in this word: “You shall love your neighbor as yourself.”