Here is an exposition of the doctrine of sin as historically held by Protestants, per the Westminster Larger Catechism (don't overlook the answer to Q152):
Q. 150. Are all transgressions of the law of God equally heinous in themselves, and in the sight of God?
A. All transgressions of the law of God are not equally heinous; but some sins in themselves, and by reason of several aggravations, are more heinous in the sight of God than others.
Q. 151. What are those aggravations that make some sins more heinous than others?
A. Sins receive their aggravations,
1. From the persons offending: if they be of riper age, greater experience or grace, eminent for profession, gifts, place, office, guides to others, and whose example is likely to be followed by others.
2. From the parties offended: if immediately against God, his attributes, and worship; against Christ, and his grace; the Holy Spirit, his witness, and workings; against superiors, men of eminency, and such as we stand especially related and engaged unto; against any of the saints, particularly weak brethren, the souls of them or any other, and the common good of all or many.
3. From the nature and quality of the offence: if it be against the express letter of the law, break many commandments, contain in it many sins: if not only conceived in the heart, but break forth in words and actions, scandalize others, and admit of no reparation: if against means, mercies, judgments, light of nature, conviction of conscience, public or private admonition, censures of the church, civil punishments; and our prayers, purposes, promises, vows, covenants, and engagements to God or men: if done deliberately, wilfully, presumptuously, impudently, boastingly, maliciously, frequently, obstinately, with delight, continuance, or relapsing after repentance.
4. From circumstances of time and place: if on the Lord’s day, or other times of divine worship; or immediately before or after these, or other helps to prevent or remedy such miscarriages: if in public, or in the presence of others, who are thereby likely to be provoked or defiled.
Q. 152. What doth every sin deserve at the hands of God?
A. Every sin, even the least, being against the sovereignty, goodness, and holiness of God, and against his righteous law, deserveth his wrath and curse, both in this life, and that which is to come; and cannot be expiated but by the blood of Christ.
