Follow the progression of these words. They're an example of how something very noble can be corrupted by several clever twists and turns of the human mind.
vig·il ˈvijəl/
noun: vigil; plural noun: vigils
a period of keeping awake during the time usually spent asleep, especially to keep watch or pray.
(in the Christian Church) the eve of a festival or holy day as an occasion of religious observance.
vig·i·lantˈvijələnt/ adjective: careful watch for possible danger or difficulties synonyms: watchful, observant, attentive, alert, eagle-eyed, hawk-eyed, on the lookout, on one's toes, on the qui vive; vig·i·lan·teˌvijəˈlan(t)ē/ noun: vigilante; plural noun: vigilantes member of a self-appointed group of citizens who undertake law enforcement in their community without legal authority, typically because the legal agencies are thought to be inadequate.
It may also explain why vigilance is left behind by so many modern spiritual leaders. Keeping watch used to be an important function of any person serving in a leadership capacity. Throw back to the day you were selected to be hall monitor in elementary school. Your teacher wanted you to keep watch over things, be vigilant. If you were bold enough to call down a friend for breaking in the water fountain line they'd likely say, "who appointed you to be king of the water fountain line?" It's how the fiercely independent and sinful human mind works: vigil to vigilant to vigilante. Please, give me a break! And, please, for all that is good and holy, raise up some vigilant spiritual leaders for our morally corrupt world!
Yes, believers are expected to keep watch over their own hearts and lives.
Keep your heart with all vigilance for from it flow the springs of life.
Proverbs 4:23, ESV
Be watchful, stand firm in the faith, act like men, be strong.
1 Corinthians 16:13, ESV
Examine yourselves, to see whether you are in the faith. Test yourselves. Or do
you not realize this about yourselves, that Jesus Christ is in you?—unless indeed
you fail to meet the test!
2 Corinthians 13L5, ESV
Watch yourselves, so that you may not lose what we have worked for, but
may win a full reward.
2 John 1:8, ESV
Be sober-minded; be watchful. Your adversary the devil prowls around like a
roaring lion, seeking someone to devour.
1 Peter 5:8, ESV
Still, the vagaries of human sinfulness being what they are this watchfulness assumes layers of personal accountability when we are gathered into community. In the wisdom of his ways God calls and appoints spiritual leaders to provide example, counsel, and spiritual guidance to Christ's body, the church. And, one of the legitimate roles of a biblical spiritual leader is the care of that body and the watchful spirit to guide it. Once again, Scripture is our guide----
Pay careful attention to yourselves and to all the flock, in which the Holy Spirit
has made you overseers, to care for the church of God, which he obtained with
his own blood.
Acts 20:28, ESV
I appeal to you, brothers, to watch out for those who cause divisions and create
obstacles contrary to the doctrine that you have been taught; avoid them.
Romans 16:17, ESV
Keep a close watch on yourself and on the teaching. Persist in this, for by so
doing you will save both yourself and your hearers.
1 Timothy 4:16, ESV
Obey your leaders and submit to them, for they are keeping watch over your
souls, as those who will have to give an account. Let them do this with joy and
not with groaning, for that would be of no advantage to you.
Hebrews 13:17, ESV
Shepherd the flock of God among you, exercising oversight not under
compulsion, but voluntarily, according to the will of God; and not for sordid gain,
but with eagerness;
1 Peter 5:2, ESV
And, of course, there are many others. The watchfulness or vigilance of spiritual leaders is a staple of God's expectation for the church and the oversight of his people.
Again, however, this is the age of the low expectation church and reduced standards of expectations regarding church membership and participation in mission. This was brought home to me several years ago when i approached a church leader about his drunken behavior in a Charleston restaurant. He embarrassed his wife and family, himself, and Christ. My approach was as gentle and loving and I could make it. He immediately said, "What i do outside the church or in my home is none of your business!" As nicely as I could I responded---"I'm sorry you are wrong. One day you and your family walked down the aisle of our church and made it my business. When you accepted a role as a leader in our church you made it my business again."
In perplexing times like these spiritual leaders need to pack plenty of vigilance in their character gear for the journey. Without it, we're not biblical leaders. And, the church is not a biblical body.