Does God view unintentional sin differently?The Old Testament makes some interesting differentiations between unintentional sins and sins done "with a high hand" (Numbers 15:27–31). While this differentiation was necessary under the Law, under the new covenant there is no longer a need for this differentiation.
The Old Testament Law says, "If anyone sins unintentionally in any of the Lord's commandments about things not to be done, and does any one of them, if it is the anointed priest who sins, thus bringing guilt on the people, then he shall offer for the sin that he has committed a bull from the herd without blemish to the Lord for a sin offering" (Leviticus 4:2–3). The rest of the chapter gives the specific offerings that should be given if a leader or the whole congregation sins unintentionally. The word for unintentional here means "inadvertent," meaning the sin was not planned out or thought through beforehand. These sins were still wrong, and the person who committed the sin was still in need of atonement, which is why there is a specific sacrifice prescribed for it.
Elsewhere in the Law, there is a reference to a different kind of sin than unintentional sin, and that is a sin done "with a high hand," meaning the doer has an attitude of defiance towards God: "But the person who does anything with a high hand, whether he is native or a sojourner, reviles the LORD, and that person shall be cut off from among his people. Because he has despised the word of the LORD and has broken his commandment, that personal shall be utterly cut off; his iniquity shall be on him" (Numbers 15:30–31). The punishment for intentional sins is more severe because of the attitude of the sinner, not because the sin itself.
The New Testament doesn't make any specific differentiation between intentional and unintentional sin. It does make clear that all humans have sinned and are separated from God (Romans 3:23; 6:23). Apart from His intervention, there would be no forgiveness of sin (Romans 5:6–11). The book of Hebrews explains a new covenant, ushered in by Jesus. The Old Testament sacrificial system foreshadowed what Jesus would accomplish on the cross. Hebrews 10:1 explains, "For since the law has but a shadow of the good things to come instead of the true form of these realities, it can never, by the same sacrifices that are continually offered every year, make perfect those who draw near." It goes on to explain how Jesus' sacrifice is a once and for all sacrifice: "we have been sanctified through the offering of the body of Jesus Christ once for all" (Hebrews 10:10); "But when Christ had offered for all time a single sacrifice for sins, he sat down at the right hand of God" (Hebrews 10:12).
Anyone who loves God, acknowledges Christ's death and resurrection, and accepts Him as his Lord and Savior has become a new creation, with God's spirit living inside of him (John 3:16–18; 2 Corinthians 5:17–21; Ephesians 1:13–14). Those who reject God's love and His offer of salvation live their lives sinning with a high hand (Romans 1:18–32; Hebrews 10:26–31). All who accept Jesus' work on the cross on their behalf are forgiven of all their sins—whether unintentional or intentional. All those who continue to reject Jesus remain condemned (John 3:36). The offer of salvation is open to all who will receive it. Jesus' death on the cross is sufficient for all of our sins—whether "big" or "small," done in defiance or in ignorance. It is only through Him that we can be saved (Ephesians 2:1–10; Acts 4:12).
Those who belong to Jesus are forgiven of all their sin. They are also transformed and made new, but that transformation is a lifelong process (Philippians 1:6; 2:12–13). We will still struggle against sin, and Jesus is still faithful to cleanse us (1 John 1:9). Paul describes this constant battle between the Spirit and the flesh: "For I delight in the law of God, in my inner being, but I see in my members another law waging war against the law of my mind and making me captive to the law of sin that dwells in my members" (Romans 7:22–23). Since we are no longer judged by the Law, there is no condemnation for those who are in Christ (Romans 8:1). However, this is not an excuse to sin. Those who are truly born again do not want to walk in sin because it separates us from God: "How can we who died to sin still live in it?" (Romans 6:2).
As Christians, we have the choice to sin or not to sin, so choose life. We have changed hearts and the Spirit of God living within us, so "Let not sin therefore reign in your mortal body, to make you obey its passions. Do not present your members to sin as instruments for unrighteousness, but present yourselves to God as those who have been brought from death to life, and your members to God as instruments for righteousness. For sin will have no dominion over you, since you are not under the law but under grace" (Romans 6:12–14).
What is sin?
How can I know what is a sin and what isn't?
Is there danger in unconfessed sin?
Will God forgive me?
How can I get right with God?
Truth about Sin