In some ways it will feel like it. There will be likely be fewer people attending the worship gathering you are part of, at least initially. It will feel different. There will be people you know that you will see less often, if they choose to attend at a different time. There will be some discomfort in all of us the first few weeks. There will likely be some "wilderness" time when we will feel like things were better back in Egypt (Numbers 14:3) and the only "rational" response would be to go back there.
But, like the Israelites, we must understand that the future God has for us will not be found in our rear-view mirror. And, His future, will require us to make sacrifices and make room. It is "making room" that is the key. Not only must we intentionally "make room" for newcomers; we must also allow God to use us to "fill it up" again. God's passion is to have two (then ten) of our worship spaces filled with people who are connecting with Him and having their lives changed by the encounter. He wants people you do life with, live next to, meet on the street, work in the cubicle beside, care about - to meet Him through your invitation. Rather than fret about what we might lose, can we instead rejoice in what they might gain - if we make room?
If we just divide up the attenders we already have...we lose. But if we can catch a vision of God's love for those who are far from Him and commit to partner with Him in brining them home - our lives - and our church - will never be the same.