What does it mean to be "brothers in Christ"?

I take the expression "brothers in Christ" here, not as referring to a Christian denomination, but in its original biblical sense: Christians are "brothers in Christ" (Col 1: 2). Seeing the church as a fraternity in Christ exposes us to a radical conception of the church, very different from that which is forged in different cultural molds.

Undoubtedly, each culture tends to organize the church according to certain patterns derived from its context. In the Anglo-Saxon culture, the church is seen as a club in which various activities are carried out, coordinated by the pastor. In Spanish and Latin American culture, the church is sometimes formed around the personality of the pastor, who assumes the authority of a true "caudillo". Other cultures will favor, for example, the liturgical rigor, or more recently, capitalism favors the understanding of the church as a true enterprise, whose value is measured by its numbers. All these conceptions of the church will have to be revised, and relativized, from a biblical understanding of the church, which tells us about a group of sisters and brothers in Christ.

What does it mean to be brothers in Christ? Paul's letter to Philemon, that little New Testament document, gives us some essential keys. It is a precious document. Onesimus, a slave of Philemon, has fled from his master, who was a Christian. But Onesimus has known Paul, and he has also become a Christian. Now Paul sends Onesimus back to his master, accompanied by a letter of recommendation. It is the letter to Philemon. In it, Paul asks his friend Philemon to receive Onesimus as a brother. And this is why this letter is full of indications about what it means to be brothers in Christ.

First of all, to be brothers in Christ is a grace (verses 3 and 25). It is not something that we have achieved, achieved, not even thought about. It is a gift from God. And this gift of God implies "peace" (v. 3). Being brothers in Christ means that, being Christians, we adhere to a fraternity that breaks cultural, ethnic, and national borders, uniting people from different backgrounds in one body. The old enemies now become brothers (Eph 2,13-15). Hence, the true Christian church can never support the military adventures of some peoples against others: it is a new reality, composed of people of every race, people and nation.

We are brothers because, in that family, we all have the same Father and the same Lord, who is Jesus the Messiah (v. 3), our elder brother. In that unity, being brothers means being "collaborators" (verses 1 and 24). When Paul looked at the churches, he did not see mere "little sheep" but groups of collaborators. His very work was a team effort. In fact, if we look at the beginning of many of the letters we call "Paul's", we will see that they are not only Paul's, but that almost all of them have the signature of their collaborators (1 Thessalonians, 2 Thessalonians, Col, Fil, 1 Cor, 2 Cor, Flm, etc.).

Another characteristic of the brothers in Christ is that they are "companions" (verse 17). It is a Greek expression (koinonos) that could also be translated as "partners". The idea behind it is to have something in common. In fact, early Christianity, until the fourth century, was characterized by an intense sharing of goods, as we see in chapters 2 and 4 of the Acts. The reasoning behind Philemon's letter is just this: if Onesimus, the former slave of Philemon, is now Paul's brother, he must inevitably also be a brother of Philemon, because they are both partners. Before Onesimus was useless for Philemon (a play on words, because Onesimus means useful), but now it is useful for both Paul and Philemon (v. 11), as companions they are.

All this can be stated because the Christianity of Paul, Onesimus, and Philemon is not yet an imperial religiosity, organized in temples, but has its main center in the houses (v. 2). As is known, all the pedagogy of God in the Old Testament is directed to the concentration of the cult in a single valid temple: the temple of Jerusalem (Deut 12). But with Jesus, that temple is replaced by the temple of his body (Jn 2,19). A body that are the same believers, united in fraternity, and not the buildings of stone. As Jesus had developed his activity in the houses of Galilee, also the original Christianity was organized in houses.

There is something interesting in this love and this faith that Paul praises in Philemon. Philemon would have love and faith toward the Lord Jesus and toward all believers (verse 5). We understand what it is to have love for Jesus and for believers. We also understand what it is to have faith in Jesus. But Paul's phrase seems to indicate that Philemon's faith is also directed towards believers. What does this mean? Actually, the Greek word that we translate by "faith" can be addressed not only to God, but also to people. In those cases, it could be translated as "trust" or "loyalty". From this point of view, we can also say that being brothers in Christ means having loyal relationships, in which mutual trust is possible.