There are two kinds of potential employees and you probably have both in your organization if you are of any size: those who think of themselves as independent contractors and those who choose to be organizational members. The first group is problematic while the second group is healthier.
Independent contractors are those who are part of your ministry but who are far more committed to what they want to do than to contribute to the overall success of the organization. For an independent contractor, your ministry, be it a mission, a church or other ministry is simply a platform for them to do their thing in their way and in light of their priorities. So while they may be employees or staff and receive their paycheck from your organization their loyalty is not to the organization and its mission but to their thing and their mission. They actually hurt your organization rather than help it.
What this means is that they have no desire or intention to align themselves with the organization itself but use the organization for their purposes. It brings with it significant lack of alignment, an independent spirit that does not play well on a team, continual push back when asked to abide by organizational values and commitments and often a passive aggressive attitude that pays lip service to the organization but in reality plays to their own priorities.
Contrast this with staff who understand that they are part of an organization and want to contribute to the mission and ethos of the organization. They play well together, abide by organizational commitments, understand that they are not solo players and deeply desire to contribute to the whole. Thus they play well on the team and exhibit a humble spirit of service and contribution to the whole.
In my experience, independent contractors do not belong in a healthy organization because they will not contribute to the whole. Those who understand that they are part of the whole and want to contribute to the whole are highly valued by an organization. If you are struggling with a staff member who does not seem to be aligned ask yourself if you are dealing with an independent contractor rather than an organizational member. That distinction is often the source of frustration that you are feeling.
One caveat. You cannot ask staff to be part of an organization when there is not clarity as to what the organization is about. Where there is a lack of organizational clarity you will have independent contractors because they have to make up their own clarity. When the organization has clarity, you can build a unified, aligned team of organizational members.