I often find myself in conversations with people who advocate against legislating morality in an attempt to "preserve the agency" of others. They say, "I would never ________, but it’s not my place to make it illegal for others to do it. We should preserve their agency and let them choose on their own whether to indulge in those acts." I understand the logic of the argument, but through my studies I have come to strongly favor legislating morality. Here are some great quotes that have helped me to come to this position:

LDS General Authorities

President Boyd K. Packer

"Covenants"

"Life is meant to be a test to see if we will keep the commandments of God. (See 2 Ne. 2:5.) We are free to obey or to ignore the spirit and the letter of the law. But the agency granted to man is a moral agency. (See D&C 101:78.) We are not free to break our covenants and escape the consequences.”

"Our Moral Environment"

"The phrase ‘free agency’ does not appear in scripture. The only agency spoken of there is moral agency, ‘which,’ the Lord said, ‘I have given unto him, that every man may be accountable for his own sins in the day of judgment.’ (D&C 101:78; italics added.)"

"Regardless of how lofty and moral the ‘pro-choice’ argument sounds, it is badly flawed. With that same logic one could argue that all traffic signs and barriers which keep the careless from danger should be pulled down on the theory that each individual must be free to choose how close to the edge he will go.

"While we pass laws to reduce pollution of the earth, any proposal to protect the moral and spiritual environment is shouted down and marched against as infringing upon liberty, agency, freedom, the right to choose. Interesting how one virtue, when given exaggerated or fanatical emphasis, can be used to batter down another, with freedom, a virtue, invoked to protect vice. Those determined to transgress see any regulation of their life-style as interfering with their agency and seek to have their actions condoned by making them legal. People who are otherwise sensible say, ‘I do not intend to indulge, but I vote for freedom of choice for those who do.’

"Civilizations, like Sodom and Gomorrah, destroyed themselves by disobedience to the laws of morality. ‘For the Spirit of the Lord will not always strive with man. And when the Spirit ceaseth to strive with man then cometh speedy destruction.’ (2 Ne. 26:11; see also Gen. 6:3; Ether 2:15; D&C 1:33; Moses 8:17.) God grant that we will come to our senses and protect our moral environment from this mist of darkness which deepens day by day. The fate of all humanity hangs precariously in the balance."

"These Things I Know"

"Agency is defined in the scriptures as ‘moral agency,’ which means that we can choose between good and evil. The adversary seeks to tempt us to misuse our moral agency."

Elder D. Todd Christofferson

"Moral Agency"

"In years past, we generally used the term free agency. That is not incorrect, but more recently we have taken note that free agency does not appear as an expression in the scriptures. They talk of our being “free to choose” and ‘free to act’ for ourselves and of our obligation to do many things of our own ‘free will.’ But the word agency appears either by itself or, in Doctrine and Covenants, section 101, verse 78, with the modifier moral: ‘That every man may act in doctrine and principle . . . according to the moral agency which I have given unto him, that every man may be accountable for his own sins in the day of judgment’ (emphasis added). When we use the term moral agency, then, we are appropriately emphasizing the accountability that is an essential part of the divine gift of agency. We are moral beings and agents unto ourselves, free to choose but also responsible for our choices.”

Elder Dieter F. Utchdorf

"On The Wings of Angels"

"You have agency, and you are free to choose. But there is actually no free agency. Agency has its price. You have to pay the consequences of your choices."

Elder Spencer J. Condie

"Agency: The Gift of Choices"

"I am indebted to President Boyd K. Packer, who made us aware of the fact that the term free agency appears nowhere in holy writ. Instead, the scriptures generally speak of agency or free will, but when agency is modified, it is referred to as “moral agency” (D&C 101:78; emphasis added). Because the term free agency has been used by various modern prophets, I use the terms free agency and moral agency interchangeably, aware that the latter term is more correct."

Elder David A. Bednar

Recounted by Orson Scott Card in "Figuring Out Free Agency"

"You were a free agent, but now you’ve chosen to sign with BYU-Idaho," he’d say (though I’m paraphrasing). "As long as you’re here, you live by the team rules.”

Other Resources

Scriptures

D&C 101:78

"That every man may act in doctrine and principle pertaining to futurity, according to the moral agency which I have given unto him, that every man may be accountable for his own sins in the day of judgment."

Quotes collected by Dr. Bruce Satterfield, Ph. D.

http://emp.byui.edu/SATTERFIELDB/PlanSalvation/Agency/MoralAgency.html

http://emp.byui.edu/satterfieldb/PDF/Quotes/Agency.pdf

LDSLiving.com

"One Phrase Church Leaders Never Say Anymore"

"There are several scriptures that may have influenced Latter-day Saints to start adding the word free onto agency. 2 Nephi 2:27; 10:23, D&C 58:27, and Helaman 14:30 all mention some variation of each of us being free to choose or act for ourselves."

New Era Magazine

"Free Agency or Moral Agency"

"Because the scriptures teach that we are ‘free to choose,’ ‘free to act,’ and free to do things ‘of [our] own free will’ (2 Nephi 2:27; 10:23; D&C 58:27; see also Helaman 14:30), we often use the term ‘free agency.’

"But did you know that the phrase ‘free agency’ does not appear in the scriptures? Instead, the scriptures teach ‘that every man may act in doctrine and principle … according to the moral agency which I have given unto him, that every man may be accountable for his own sins’ (D&C 101:78; emphasis added)."

Related:

"Rights, Agency, and Free Will"