It seems that as the Great Apostasy was unfolding, that there were some who took a statement of Nicolas, one of the original Seventy, out of context. We don't have exactly what he said, but evidently it was something to the effect of God is willing to forgive as often as we sin.
Misinterpreting (purposefully or not) his words, they claimed the option of total sexual license, with wives in common and free love with everyone, yet they made a great deal of effort to look good outwardly.
This is hardly just a sin particular to one period of ancient history.
Bishop Newel K. Whitney was also sternly warned:
Let my servant Newel K. Whitney be ashamed of the Nicolaitane band and of all their secret abominations, and of all his littleness of soul before me, saith the Lord, and come up to the land of Adam-ondi-Ahman, and be a bishop unto my people, saith the Lord, not in name but in deed, saith the Lord. D&C 117:11 Emphasis mineIn his Doctrinal New Testament Commentary, Elder Bruce R. McConkie said this refers to “members of the Church who [try] to maintain their church standing while continuing to live after the manner of the world . . . . [The phrase] has come to be used to identify those who want their names on the records of the Church but do not want to devote themselves to the gospel cause with full purpose of heart” (DNTC 3:446).
When we pick and choose which parts of the Gospel we want, we have already excluded the most important parts - sacrifice and humility.
Elder Neal A. Maxwell said: “Our relationship to living prophets is not one in which their sayings are a smorgasbord from which we may take only that which pleases us. We are to partake of all that is placed before us, including the spinach, and to leave a clean plate” (Things As They Really Are, p. 74).
Some of us struggle with the spinach, and that may even be normal to a degree. But it is when we have been given time to learn for ourselves, and we still refuse, that we tread dangerously.
Joseph had this to say in Lectures on Faith
"It is in vain for persons to fancy to themselves that they are heirs with those, or can be heirs with them, who have offered their all in sacrifice, and by this means obtained faith in God and favor with him so as to obtain eternal life, unless they, in like manner, offer unto him the same sacrifice, and through that offering obtain the knowledge that they are accepted of him."...
"But those who have not made this sacrifice to God do not know that the course which they pursue is well pleasing in his sight; for ...where doubt and uncertainty are there faith is not, nor can it be. For doubt and faith do not exist in the same person at the same time; so that persons whose minds are under doubts and fears cannot have unshaken confidence; ...and where faith is weak the persons will not be able to contend against all the opposition, tribulations, and afflictions which they will have to encounter in order to be heirs of God, and joint heirs with Christ Jesus; and they will grow weary in their minds, and the adversary will have power over them and destroy them." Lectures on Faith, Lecture 6, paragraphs 8,12
We can not live after the manner of the world, or incorporate it into the Church, without destroying either the Church and/or ourselves.