Guard

In 2 Kings 17, after warning them to change their ways, the LORD removed His people of the northern kingdom of Israel from the land, and sent them into exile in the hands of their captors and conquerors, the Assyrians, because they mixed the worship of idols with their worship of Him. They stiffened their necks and rejected the LORD's warning to turn from these ways, and they continued to follow idols. Israel chose to follow the ways of the nations around them. They rejected His covenant (v. 13-15).
The conquering Assyrians filled the now empty land of Samaria (meaning Watch mountain-to guard, protect, to keep watch, to preserve), in Israel, with foreign inhabitants from various cities under their rule. They did this so the land would not be empty and uninhabited (v. 24).
These various peoples brought by the Assyrians into the land of Samaria came with their gods and pagan practices.
The Assyrians brought people from Babylon (Confusion, to mingle by mixing) into the land. These Babylonians brought with them the practice of making Succothbenoth, a demonic version of a tabernacle, where booths are established as brothels to worship idols with promiscuous and perverse sexual activity.
The Assyrians brought in people from Cuttah (Crushing), who worshipped Nergal (Hero), the planet Mars.
People from Ava (Ruin, distortion, overthrow, twisted, perverted) were also brought to the land. They worshipped Nibhaz, an idol in the shape of a dog, representing the lord of darkness.
Foreigners from Hamath (Fortress, walls of defense) came. They brought with them the worship of Ashima (Guiltiness: "I will make desolate") and Tartak (prince of darkness in the form of an ass).
The Assyrians also brought in people from Sepharvaim (Enumeration), who practiced the burning of their children in fire to the gods of Adrammelech (glorious, majestic prince), and Anammelech (idolatrous image of the king).
So the territory, Samaria, that was meant to guard, preserve, keep watch over, and protect the ways of the LORD, became a land filled with idol and demon worshipping foreigners because Samaria did not fulfill their God-given purpose, and went after other gods themselves. They mixed the profane things of this world with the holy things of God. They mixed His truth with the lies of demons.
The foreign people who had been brought into the land of Samaria, began being attacked and killed by lions (v. 25). The king of Assyria was told that this was happening because the new-comers did not know the God of the land, the God of Israel. A priest was brought back to teach them about the LORD God. The foreigners learned the knowledge of the LORD, but also continued to practice their idolatry as well (v. 26-29). These practices continued generation after generation for many years (v. 41).
Like Samaria, we believers are equipped by God to be a watch mountain, a preserver, a protector of the truth of God's word, and His covenant. Even worse comes upon the land as the people of God forget their covenant truths, and mix the commandments of men and the world, with the word of God (Mt. 15:9, Col. 2:20-22). The land becomes filled with ungodly beliefs and practices that affect not only the present generation, but generations to come.
The responsibility for preserving the truth of God, lies not with the ignorant, but with the people of God. It was the Samarians who broke covenant and followed ungodliness, even after warnings, when they were the ones who should have been watching, guarding, protecting and preserving, according to the meaning of their name. Strangers to God, brought in by the enemy, who are only nominally knowledgeable in the ways of God, are not going to do this for us, though we blame them. We are to preserve the truth and covenant in our own lives as living epistles, as the Apostle Paul wrote about us. The word is to be preserved in us, and lived through us:
"Clearly you are an epistle of Christ, ministered by us, written not with ink but by the Spirit of the living God, not on tablets of stone but on tablets of flesh, that is, of the heart. And we have such trust through Christ toward God."             2 Cor. 3:3-4

It is the covenant people of God who are to be faithful in our own lives to keeping and guarding the pure relationship with our Father that Jesus provided with His blood. 
The Book of Proverbs tells us the value of keeping the word that is written in our hearts:
"My son, give attention to My words; Incline your ear to My sayings. Do not let them depart from your eyes; Keep them in the midst of your heart; For they are life to those who find them, and health to all their flesh. Keep your heart with all diligence, for out of it spring the issues of life...Do not turn to the right or the left, remove your foot from evil."
                                                                                 Prov. 4:20-27

King David, mourning over the violence of the wicked, talks about how the LORD tests the righteous:
"When the foundations are destroyed, what hath the righteous wrought?"
                                                                                  Ps. 11:3, JPS Tanakh


Our Father has called us to be a "watch mountain", to guard, preserve, keep and protect.


"Find Us Faithful"
https://www.youtube.com/watch?v=eERKnxzNzwg