We all recognize the strength of concrete. We use it for buildings, roads, bridges, even decorations. It is cheap and easy to use, and above all, strong. Have you ever considered why concrete is so strong? I studied civil engineering in college before I decided that I would not be able to preach effectively and hold down a full-time secular job at the same time. I assumed that the engineering training would never serve me in preaching (except to build a pulpit if needed), but now I finally have found a use for it! I can tell you where concrete gets its strength. Just don’t ask me to reveal my grade in concrete materials lab.
Concrete is essentially composed of two things, rocks and glue. The glue is cement, which is what some mistakenly call concrete. The rocks are various sizes from fine sand through larger gravel. What gives concrete its strength is how the different sizes of rocks fit together. The greater the variety of sizes in the rocks the tighter they fit together. The cement only holds them in place. You can prove this by examining mortar. It is made up of the same two materials. The only difference is that mortar has only one size of rock, one particular grade of sand. It uses the same cement and is mixed just as well as the concrete. But because the sand does not fit together as tightly, nor have the strength of larger rocks, it is not nearly as strong as concrete.
Now, before everyone falls asleep or asks, “This is all very interesting, but what does it have to do with my service to Christ?” let us make an application. The church is often compared to a building (Ephesians 2:19-22). As such, our analogy to concrete as a building material is appropriate. Where does the church get its strength? Does it come from everyone thinking, acting, and speaking just alike? Or do we gain strength from the variety of thoughts, actions, and speech of different disciples? I believe this is the point that Paul addresses with the local church at Corinth in 1 Corinthians 12. They apparently did not value anyone who was not exactly like them. What did Paul tell them? He told them that the body would look pretty weird, and not function very well, if everyone was an eye, ear, or a mouth. We would certainly be able to see, hear, and condemn any perceived differences, but not much of the Lord’s business would be accomplished. Just like the mortar of an old building, the church would slowly crumble away.
Does this mean that the church would become even stronger if we would join ourselves with ecumenical groups and accepted all religious people as “brethren in prospect?” No! Do not forget the role of the cement. Kick a pile of well-mixed rocks without cement and you spread them everywhere. Kick a pile of well-mixed rocks with cement and you are likely to break your toe. I liken the cement to the blood of Jesus Christ. It is the glue that holds us together. Each rock, no matter how large or small, is cemented to the whole by their faith in that precious blood. Those “brethren in prospect” do not have that faith or they would respond in a Biblical way to the gospel. Since they are not cemented to the whole, they are not contributing to the strength of the body, like loose gravel sitting on a sidewalk.
Are you interested in making the church more like concrete or mortar? Do you value those who have the same faith in Jesus Christ that you have, but apply some scriptures in a different manner than you? Or do you seek to remove from fellowship (however you define it) those with whom you disagree on any subject? What about the local church with which you assemble? Do you value those who have different views than you? Who are we more likely to learn from, the one who agrees with us in all questions, or the one who presents a differing viewpoint? If they are unable to convince me of their view with scripture, I certainly feel no compulsion to accept the differing views, but I value the refining it gives my faith (Proverbs 27:17). I want the strength of concrete.