Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying serveth not for them that believe not, but for them which believe. If therefore the whole church be come together into one place, and all speak with tongues, and there come in those that are unlearned, or unbelievers, will they not say that ye are mad? But if all prophesy, and there come in one that believeth not, or one unlearned, he is convinced of all, he is judged of all: And thus are the secrets of his heart made manifest; and so falling down on his face he will worship God, and report that God is in you of a truth. (1 Corinthians 14:22-25)
As I read this passage this morning with my wife, I started to think about what it says in verse 22, “prophesying serveth not for them that believe not, but for them which believe.” I thought, does this mean that our preaching should not be addressed to the lost? Is the church service only for the saved? I know there are some people who believe this to some extent at least, and I think that this verse should influence the topics and purpose of our church services, generally. But verses 24-25 talk about an unbeliever being present in the service, being convicted by the prophesying, and finally worshipping God. Unbelievers will attend our church services, and when they do, they should be convinced by the preaching that they are lost without Christ and need to turn to Him for salvation.
You Think Too Much! 
We assemble for edification, disassemble for evangelism, keeping the church and the world distinct. I believe a major feature here is that a church service is designed for saved people; that is what will most benefit the lost. The big problem today is designing the services for unbelievers. Here we can say that keeping the purpose for believers has the greatest impact on unbelievers. Formatting things on Sunday for unbelievers does not fit a NT model and does great damage to the church and the unsaved, but even more greatly dishonors God. Much could be said here.
I think we are agreeing in principle here. I most definitely agree that formatting the church service for unbelievers is a problem and wrong. The church service should be designed/formatted for believers to worship, be edified, be challenged, etc. The message delivered should address unbelievers, if they are present. And according to this passage, unbelievers would be assembled with them. From this here, I don’t know how or why the unbelievers were there with them, just that they were there.
I think a proper balance would be not design the service centered around the unsaved, certainly not if that includes compromise.
Obviously from this verse it is not unscriptural for the lost to attend church. And indeed, they were concerned about the impact of the service upon the lost. Therefore, I don’t have any problem with inviting lost people to church for evangelistic reasons.
But I agree also, that the service’s primary purpose should be the edification of the believer. If evangelism is present, it has a secondary role.–>