In its article on Sin, The Catholic Encyclopedia states: "As regards the principle from which it proceeds sin is original or actual. The will of Adam acting as head of the human race for the conservation or loss of original justice is the cause and source of original sin. Actual sin is committed by a free personal act of the individual will. It is divided into sins of commission and omission. A sin of commission is a positive act contrary to some prohibitory precept; a sin of omission is a failure to do what is commanded." (http://www.catholic.org/encyclopedia/view.php?id=10849) Although most Protestant Christians would not state the matter in these terms, many of them would agree that there are different types of sins.
If we reject the premise that we have inherited Adam's sin (which is not saying that we haven't felt some of the consequences of his decision), then we are left with what the Catholics call actual sin. Traditionally, the worst of these actual sins were the Seven Deadly Sins: Lust, Greed, Glutony, Envy, Anger, Pride and Sloth. (http://www.catholicbible101.com/7deadlysins.htm) It is interesting to note that Catholics also make a further differentiation between sins by characterizing them as being mortal (those that result in damnation) or venial (those that impede our relationship with God).
All of these distinctions between different kinds of sins brings to mind another interesting question: What is sin? The Catholic Encyclopedia states that "Sin is nothing else than a morally bad act, an act not in accord with reason informed by the Divine law." For those of us who might find that definition to be a little too broad and nebulous, there are also several places in the Bible where sin is defined.
In this regard, the scripture that is most often appealed to is found in John's first general epistle. He wrote: "Whosoever committeth sin transgresseth also the law: for sin is the trangression of the law." (I John 3:4) Now this is where things get interesting in the realm of Christian theology/philosophy. What law was John talking about? Was he referring to the Law of Moses? Was he writing about the Ten Commandments? Was he talking about the teachings of Jesus Christ? In any legitimate attempt to answer these questions, one would have to examine all of the other scriptures which define sin and examine John's statement here in both the context of his other writings and those of his associates.
Another definition that was attributed to Solomon states: "Haughty eyes, a proud heart, and evil actions are all sin." (Proverbs 21:4, NLT) In his letter to the Romans, Paul said that anything that does not originate in faith is a sin. (Romans 14:23) Nevertheless, he also indicated that the Law enables us to understand what sin is. (Romans 3:20) In his epistle to the scattered tribes of Israel, James said that any occasion that a person fails to do what they know is right should be considered a sin. (James 4:17) Later, in the same letter referenced above, John declared that all unrighteousness is sin. (I John 5:17)
David once wrote that all of God's commandments are righteousness (Psalm 119:172), but Paul indicated that there was a righteousness apart from the Law - one based on faith. (Romans 3:21) Hence, in looking at these scriptures, we are forced to ask ourselves: Is there a coherent and meaningful way to reconcile these different statements about sin? This author believes that there is a way to do just that.
First, in reviewing all of the scriptures associated with the topic of sin, it becomes clear that sin is inextricably linked with disobedience to God's Law. Nevertheless, it is not immediately apparent from those scriptures alone which Law or laws are referenced in these statements.
Returning to John's definition of sin, when we take a closer look at the surrounding verses a clearer picture begins to emerge about the nature of what he was trying to convey to his readers. At the beginning of this letter we read: "This is the message we heard from Jesus and now declare to you: God is light, and there is no darkness in him at all. So we are lying if we say we have fellowship with God but go on living in spiritual darkness; we are not practicing the truth. But if we are living in the light, as God is in the light, then we have fellowship with each other, and the blood of Jesus, his Son, cleanses us from all sin. If we claim we have no sin, we are only fooling ourselves and not living in the truth. But if we confess our sins to him, he is faithful and just to forgive us our sins and to cleanse us from all wickedness. If we claim we have not sinned, we are calling God a liar and showing that his word has no place in our hearts." (I John 1:5-10, NLT)
In the original letter, there were no chapter and verse designations to interrupt the writer's thought. Hence, the thought continues into the following chapter: "My dear children, I am writing this to you so that you will not sin. But if anyone does sin, we have an advocate who pleads our case before the Father. He is Jesus Christ, the one who is truly righteous. He himself is the sacrifice that atones for our sins - and not only our sins but the sins of all the world. And we can be sure that we know him if we obey his commandments. If someone claims, 'I know God,' but doesn't obey God's commandments, that person is a liar and is not living in the truth. But those who obey God's word truly show how completely they love him. That is how we know we are living in him." (I John 2:1-5) So, according to John, Christians do sin - they break God's commandments. Nevertheless, he went on to remind his audience that they have an advocate with God - Jesus Christ. He is recounting here the most basic message of Christianity: The sacrifice of Jesus Christ atones for our sins - removes them from us - wipes them away.
Continuing, John nails down exactly which commandment(s) he's talking about. We read: "Dear friends, I am not writing a new commandment for you; rather it is an old one you have had from the very beginning. This old commandment - to love one another - is the same message you heard before. Yet it is also new. Jesus lived the truth of this commandment, and you also are living it. For the darkness is disappearing, and the true light is already shining. If anyone claims, 'I am living in the light,' but hates a Christian brother or sister, that person is still living in darkness." (I John 2:7-9) John is clearly associating the commandment(s) with the principle of love here.
Hence, when we return to his definition of sin delivered later in the letter, we begin to understand what he is really talking about. In context, we read: "Everyone who sins is breaking God's law, for all sin is contrary to the law of God. And you know that Jesus came to take away our sins, and there is no sin in him. Anyone who continues to live in him will not sin. But anyone who keeps on sinning does not know him or understand who he is." (I John 3:4-6) But didn't John say that Christians sin? Keep reading! "Dear children, don't let anyone deceive you about this: When people do what is right, it shows that they are righteous, even as Christ is righteous. But when people keep on sinning, it shows that they belong to the devil, who has been sinning since the beginning. But the Son of God came to destroy the works of the devil. Those who have been born into God's family do not make a practice of sinning, because God's life is in them...Anyone who does not live righteously and does not love other believers does not belong to God. This is the message you have heard from the beginning: We should love one another...If we love our Christian brothers and sisters, it proves that we have passed from death to life. But a person who has no love is still dead." (verses 7-14)
Paul wrote to the saints at Rome: "Love does no wrong to others, so love fulfills the requirements of God's law." (Romans 13:10) As with many Christians today, the Pharisees and Sadducees loved to embellish the Law and add to the list of things that were considered sins. We are informed in three of the Gospel accounts of Christ's life, that one of them asked him "Teacher, which is the most important commandment in the law of Moses?" (Matthew 22:36) Continuing: "Jesus replied, 'You must love the Lord your God with all your heart, all your soul, and all your mind. This is the first and greatest commandment. A second is equally important: Love your neighbor as yourself. The entire law and all the demands of the prophets are based on these two commandments.'" (verses 37-40) In other words, love is the principle behind the whole edifice of the Law.
In its most fundamental and basic terms, even the Ten Commandments can be reduced to this formula. The first four commandments are based on love for God, and the last six commandments are based on love for our brothers and sisters. Hence, for Christians, when we put all of the scriptural and philosophical evidence together, the clearest definition of sin is "Any behavior that is not motivated by love." (And for all of the haters out there, that includes loving yourself!)