Satan does not create. He cannot. He only destroys what others create.
Since life itself is sacred, and he cannot create life, he shows his "great power" by taking life. This is the reason he taught murder to Cain, because if life is among the greatest of gifts from God, Satan's secret work of murder attacks the power of creation. (See Moses 5: 29-32.)
If you want to know where Satan's great work is prospering anytime in history, look for those groups who organize to kill others. Those who preach hate, lead to violence, lead to murder and ultimately mass killing. These are the ones who do not create, nor do they respect the great gift of creation given by God to mankind. These are they who are overcome by the devil, who love a lie, who make war with God and will ultimately succeed in completely rejecting what He has offered to them. (See D&C 76: 28-37.)
Murder of the innocent is one of the unpardonable sins. (See D&C 132: 19) It is so offensive because it undoes the great gift of life given by God. It is a direct challenge to God's authority. He alone holds the keys of life and death. Killing directly invades God's authority.
We live at a time when there are organized efforts to form groups for the sole purpose of killing others. This behavior is so directly analogous to the Gadianton conspiracy within the Book of Mormon that the lessons there should serve as notice to us. Moroni interrupted his translation of the Book of Ether to give us this warning:
20 And now I, Moroni, do not write the manner of their oaths and combinations, for it hath been made known unto me that they are had aamong all people, and they are had among the Lamanites.
21 And they have caused the adestruction of this people of whom I am now speaking, and also the destruction of the people of Nephi.
22 And whatsoever anation shall uphold such secret combinations, to get power and gain, until they shall spread over the nation, behold, they shall be destroyed; for the Lord will not suffer that the bblood of his saints, which shall be shed by them, shall always cry unto him from the ground for cvengeance upon them and yet he avenge them not.
23 Wherefore, O ye Gentiles, it is wisdom in God that these things should be shown unto you, that thereby ye may repent of your sins, and suffer not that these murderous combinations shall get above you, which are built up to get apower and gain—and the work, yea, even the work of bdestruction come upon you, yea, even the sword of the justice of the Eternal God shall fall upon you, to your overthrow and destruction if ye shall suffer these things to be.
24 Wherefore, the Lord commandeth you, when ye shall see these things come among you that ye shall awake to a sense of your awful situation, because of this asecret combination which shall be among you; or wo be unto it, because of the blood of them who have been slain; for they cry from the dust for vengeance upon it, and also upon those who built it up.
25 For it cometh to pass that whoso buildeth it up seeketh to overthrow the afreedom of all lands, nations, and countries; and it bringeth to pass the destruction of all people, for it is built up by the devil, who is the father of all lies; even that same liar who bbeguiled our first parents, yea, even that same liar who hath caused man to commit murder from the beginning; who hath chardened the hearts of men that they have dmurdered the prophets, and stoned them, and cast them out from the beginning.
26 Wherefore, I, Moroni, am commanded to write these things that evil may be done away, and that the time may come that Satan may have ano power upon the hearts of the children of men, but that they may be bpersuaded to do good continually, that they may come unto the fountain of all crighteousness and be saved.
Having said the foregoing, let me add that I do not think knowing our awful circumstance does a thing to fix it. What fixes it is to have more people come to the Lord, develop love for their fellow man, and live the commandments given by Him. That is something done one person at a time. I despair when I think in larger numbers than the individual. I rejoice when I think of the single person. For anything is possible with each person, no matter what their circumstances.