Jesus famously said that those considering following him should first count the cost. His point was that they were going to face persecution and have to be willing to give up their life. They would lose friends and influence for the sake of the Gospel but the Gospel is worth it.
Jesus’ words were not primarily about churches and their vision/mission. However, whilst recognising this is not a straight and strict application, I think the principle is true when it comes to this too. Indeed, you could argue that until the price tag is attached, you don’t have a vision or mission, just some dreams.
A church needs to recognise that there is a cost to who they are trying to be and what they are seeking to do in their context. This ill divide into two parts, there’s one off capital costs and ongoing running costs. Capital costs might include purchase of property and its development. Running costs will include salaries, resources etc.
Both of these are to some extend fixed and objective. A church of a certain size with a desire to grow to a given level and seeking to be engaged in particular ministries into the community will need specific facilities. Generally speaking, whether or not you buy land and build or you buy existing property and develop it, you’ll probably find that it amounts the roughly the same level. You might pay £800,000 for a ready to move into facility £400,000 for a building and a further £400,000 changing and improving it.
What I would encourage you to do is to be up front about the cost, even if it sounds like a big number. First, you want the church to buy into the vision fully, understanding all the implications. You also want to build faith. The question is “can we trust God to provide that?” The answer has to be “Yes.” This means that there is a second part of the question which is “How is this going to happen?” There’s more than one way in which God can give you that facility. He might make the full amount of money available to you through gifts. He might give the church family the faith to give into the project over time. He might enable you to have a favourable mortgage and give you the capacity to repay it (the money then becomes part of day to day outgoings). It is also possible that God might give you the property for free or at a reduced price, moving a current owner’s heart. He might allow you to move into somewhere and grow grow into it, developing more of the space over time. Incidentally, whilst you need full buy in to the vision and its cost, I think that it is best to allow those operationally responsible freedom in terms of how you go forward.
Similarly, your church, given its size, context and dreams may want to recruit staff. You will need a certain number of staff to meet that and there is then a salary cost. Now, the reality is that most churches are working with a gap between what they can afford and what the true cost is for their vision here. What I mean is that a church seeking to employ two Gospel workers often has the kind of expectation of a worker in terms of qualifications, expectations and capacity. The kind of worker they have in mind could easily command between £40,000 and £80,000 in secular work (possibly more). Few churches, if any could afford that for one worker let alone more. Yet the reality is that God provides, God gives. The way he tends to do that is that he gives workers the heart and enables them to be willing to come and work for much less. That includes making available workers who are able to give up the whole of their time to the church for free. Again, we need to be up front with those joining our church or signing up to the vision that there is a cost. We need to be saying that the true monthly/annual cost for a church of our size and with our vision is x amount.
This encourages church members to be praying into the vision, they can be specific in their requests to God. It also helps them to think about how they can help, how God might give through them. This might mean that they are able to increase their financial giving, it might mean that they can give their time and skills for free, or it might mean that they start talking o others who are able to support in some way.
The tough part is that this also enables people to know what they are saying yes r no to and for some people, it might mean that they say “no.” This means either that you listen to them and the vision has to change because you realise that God is using them to challenge you or it might mean that some people choose not to be part of the specific vision/mission.