What do you mean by “Ultimately, these sins will cause you to lose your salvation”? Once saved, always saved.
See: Once Saved, Always Saved.
Without eternal security then the whole concept of being a ‘born again’ Christian is meaningless. A person would never know if they are going to heaven or hell. I’m in my 50's so if I had rebelled for a couple of decades then came back to the Lord, I might have a chance but would never be 100% certain. My 14 year old son, if he does the rebelling thing and he dies or the Lord comes before he comes back to the Lord, he will be in hell. He was saved when he was five. I have never heard of this twist view of the Scriptures before. Everyone makes mistakes.
I am glad I didn’t order your book for my teenage son because of the bad doctrine. Scary and very sad. You have to go through life not really knowing where you are going to end up after this life, whereas I am 100% certain I am going to be in heaven.
"Now by this we know that we know Him, if we keep His commandments. He who says, "I know Him," and does not keep His commandments, is a liar, and the truth is not in him. But whoever keeps His word, truly the love of God is perfected in him. By this we know that we are in Him. He who says he abides in Him ought himself also to walk just as He walked" (I John 2:3-6).
Hymenaeus is an example of a man who once had been enlightened, but not saved. He never accepted Jesus into his heart.
"This charge I commit to you, son Timothy, according to the prophecies previously made concerning you, that by them you may wage the good warfare, having faith and a good conscience, which some having rejected, concerning the faith have suffered shipwreck, of whom are Hymenaeus and Alexander, whom I delivered to Satan that they may learn not to blaspheme" (I Timothy 1:18-20).You cannot deliver someone to Satan if he never left Satan. You cannot suffer shipwreck on a boat you have not boarded.
"And their message will spread like cancer. Hymenaeus and Philetus are of this sort, who have strayed concerning the truth, saying that the resurrection is already past; and they overthrow the faith of some" (II Timothy 2:17-18).You cannot stray from some place you never were.
Sorry but you are naďve regarding your statement: “I only know of a few religions that elevate chastity as a special form of religious expression.” The Brethren (closed or Plymouth) firmly believe and teach that all sex is wrong, even sex in marriage if not for procreation purposes only. (You are never to enjoy, as my father said, even married sex is “defiling”).
"Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4).
I agree but not the Brethren group.
The original statement still stands: "I only know of a few religions that elevate chastity as a special form of religious expression."