Have you noticed that there are many churches out there? It is intimidating! Especially those really BIG churches.
I admit that it is hard to subdue my competitive feelings about other churches. There is a dark corner of my heart where I think that my church is the best - the one true church - the one place where the doctrine is pure and the practice is biblical. Of course that means that any church that is not this church is in some way deficient. All true believers should come join my flock for the glory of God!
I try to keep such feelings in check by keeping a few important facts in view.
The first fact is that I don't have a church to call my own. I am simply a follower of Jesus Christ and the only true church is HIS church. The local church I pastor is not mine, but His. He equips His servants as He sees fit and assigns them to the local flock as He knows best. I am responsible to Him for the care I give the sheep that He assigned to me. (1Peter 5:2-4; Hebrews 13:17) I have plenty of legitimate pursuits to occupy my time - rustling sheep from other flocks is not one of them.
The second fact is that God loves diversity. Take a look at His creation and this is immediately obvious. How many types of biomes, plants, animals, etc. are there? Are any two people exactly alike? It is, therefore, no surprise to find that churches are diverse even when they share the same basic doctrine of salvation by grace through faith in Jesus Christ. There are diverse personalities, histories, and cultures that contribute to people's choices of diverse local churches.
The third fact is that God has not yet perfected us. (James 3:2; 1John 3:2) As a result, there is such a thing as "disputes over doubtful things." (Romans 14) Some people have scruples about one thing and other people don't see it that way. According to Scripture we shouldn't look down on people who see things like that differently than we do - rather we are to be sensitive to their feelings and do what we believe is right in the sight of the Lord. "Whatever is not from faith is sin." (Romans 14:23)
The fourth fact is that church growth isn't even a good goal unless it comes from the conversion of new Christians. If "growth" comes by siphoning Christians from some other local church, then it is really only redistribution. Sometimes people visit my church because of some interpersonal conflict in their home church. It is my practice to try to help them reconcile to their previous church and pastor. People should not be hopping from church to church, especially if it is just because they can't get along with other people. Sometimes people SHOULD change churches, but the threshold for that decision should involve significant matters of theological conviction - rather than the prevalent wanderlust of modern consumer culture.
I am CERTAINLY NOT endorsing every group that calls itself a church - not by a long shot. All "churches" are more or less "religious," but many don't preach the Bible and don't teach the true Gospel of Jesus Christ. No genuine follower of Jesus Christ has any business in a place like that. People in such "churches" need to be evangelized.
Some churches are a kind of Christian food court. They find the most minimal basis for agreement and are careful not to talk about anything that "Christians" might disagree about. Everyone comes together and has a great religious time in a nominally Christian way without ever getting much deeper into the Bible than the idea that there is a God. These are like the home on the range, "where never is heard a discouraging word and the sky is not cloudy all day." (Howdy Doody 3:16)
Can you tell I don't think that genuine Christians should play these market driven games? The people who do this dishonor God and neglect His Word. In contrast, the Bible says that pastor/teachers are given to the church to equip them for ministry so that they grow up in the truth and are "no longer children, tossed to and fro and carried about with every wind of doctrine..." (Ephesians 4:11-16) People in such settings need to be discipled into mature Christian discernment so they can "...test the spirits - whether they are of God" or not. (1John 4:1) There are, after all, "many false prophets."
Our loyalty is not to everyone who uses the title "Christian" much less everyone who is "religious." Our loyalty is to Christ Himself. As followers of Christ we need to submit to His word, obey as best we can, be careful about compromise, and do our best to bring others to Him for salvation. We look to the Master and not at what He has given others to do.
IN CONCLUSION: The other churches are not "the competition." Being the church isn't competitive... it is a matter of simple obedience to Jesus Christ. We who serve Jesus labor at planting and watering - but we wait on Him to give the increase when, how, and where He chooses. (1Corinthians 3) How can we help but cheer for every soul brought from death to life?