Vigilance means to be watchful, specifically a careful watch regarding areas presenting danger or difficulty.

Few areas rival the need for leaders to be vigilant concerning their responsibilities.

Leaders carefully watch over…
…the spiritual growth and development of each Christian.
…the physical concerns inside and outside of the church.
…the influence of the church within the community.
…the missional outreach of the gospel to the world.

The list could address more but the direction is obvious.

The responsibility is great and when leaders are vigilant to the task before them they can take advantage of beautifully choreographed God given opportunities.