In order to understand the role of the Christian in society, we must first biblically understand who the Christian is, and then move on to understand what he or she is commissioned to be and do by the Lord and Savior Jesus Christ.
The first people to be called ‘Christian’ were the disciples of Jesus Christ (Acts 11:26). These disciples were people who have repented from their sins and believed Jesus Christ as their Lord and Savior, after hearing the Gospel (Acts 2). They were not called Christians by fellow believers, but by non-Christians – the society.
Why were the disciples of Christ called Christians? Because they were living according to the teachings of Jesus Christ through their living and verbal testimony. In other words, they were witnesses of Christ to others around them as commissioned by Jesus Christ (Mathew 28:18-20; Mark 16:15–16; Luke 24:44 –49; John 17:18; Acts 1:8). Therefore, Christians are saved persons, believers and followers of the Lord Jesus Christ, and their role in any given society is to be a witness of Christ.
For a Christian to fulfill this role of witnessing Jesus Christ to the world, he or she needs to understand what it means to be a witness and how witnessing should be done. In this context, witnessing means proclaiming what you have heard, seen, learned, believed and experienced about Jesus Christ by living an exemplary Christian life and through verbal expression. To be a witness of Christ to the world is to proclaim and represent Christ correctly in your beliefs, teachings, character, and work (2 Corinthians 5:14–21). As eye witnesses of the life, ministry, death, resurrection, and ascension of the Lord Jesus Christ, the Apostles and the early Christians proclaimed what they have seen, heard, touched, and experienced in light of the inspired written Word of God (1 Corinthians 15:1–11; 1 John 1:1–4).
Christians who are living after the apostolic era, like you and me, are to witness Christ according to the inspired, complete, sufficient, inerrant, and authoritative written Word of God (Acts 20:25–27; 2 Timothy 3:14–17; Jude 3–4). God, who has guided and superintended the writing of the Old Testament, has also used, empowered, guided and superintended the Apostles and other disciples who worked closely with Apostles to write the New Testament (John 16:13; 2 Peter. 1:16–21). The New Testament (NT) is rooted on the teaching of the Old Testament (OT), and they both point us to Jesus Christ who is the whole mark of the Scripture. The OT points to Christ and the NT presents Him (Luke 24:44–47). Thus, the account of Christ, His work, teaching and mission in the world that Christians should give witness to, is recorded in the whole Bible (the inspired 66 books of the Bible from Genesis to Revelations). Scripture contains all that men need to learn and believe for anyone to be saved through repentance and faith in Jesus Christ, and to live a godly life in this present age, as he or she is waiting for the blessed return of Jesus Christ (2 Timothy 3:13–4:5; 2 Peter 1:3–21). The Bible clearly teaches how Christians should live in the church, in their homes, in their communities, in their works places, and all areas of influence so that they can witness Christ faithfully (Ephesians 4:11—6:20; 1 Timothy 4:12–16; Titus 2—3). Therefore, Christians today and until Christ returns are to read, study, understand, believe, teach, and live out what the inspired Scriptures teach as they are empowered by the Holy Spirit.
You cannot separate faithful witnessing from the faithfulness of the Word of God in belief, teaching and in living (1 Timothy 4:15-16). Consequently, you cannot separate faithful witness from being a Christian, as that is something intrinsic to the new being (1 Peter 2:9).
Since faithful witnessing cannot be separated from faithfulness to the Scripture, to witness Christ faithfully to the world, Christians must read and study the Word of God correctly and prayerfully to understand it correctly, believe the truth, and then live rightly according to the Word of God, applying it appropriately in every aspect of their lives. Christians must study their Bibles in order to see how Christ lived, and what He has taught, so that they may teach and practice everything He has commanded them to teach and imitate what they are commanded to imitate about Him. It is the biblical teaching of Christ, the lives of believers that are transformed by the Gospel, the prayers of these believers, and the righteous actions of these Christians that witness Christ to their societies.
Moreover, in order to fulfill the role of a Christian in the society, Christians must live according to the complete, undiluted and unpolluted gospel of Christ in their homes, congregations, communities, work places, and in the society at large. Christians must act in line with the doctrine that they claim to believe. Christians are custodians of truth and moral uprightness. This is why the church (body of Christians) is called the pillar and ground of the truth in the society (1 Timothy 3:15). In marriage, homes, business, in politics, wherever they are and in whatever they do, Christians must abhor what is evil and cling to what is good (what is approved by God) – Romans 12:9; 1 Corinthians 10:31. Christians are to stand up for Christ and for righteousness. Christians are called to be the light of the world through their godly living, through biblical teachings and through righteous actions (Mathews 5:13–16, Colossians 3:1–17). Where a Christian has sinned, he/she must repent off his/her sin, admit it, confess it, ask for forgiveness from God and from people he/she has sinned against, and then continue pursuing righteousness (1 John 1:5–2:6), as this is part of witnessing.
Furthermore, Christian must teach and preach this pure, complete and undiluted gospel to other people so that others may repent from their sins and believe Jesus Christ in order to be saved and to live transformed God pleasing lives (Titus 2–3). The primary role of Christians in the society is to teach and preach the gospel of Christ in life and doctrine to restore the worship and glory of God in sinner.
The role of the Christian in the society cannot be fulfilled by the cleverness and human wisdom (John 6:44; 15:1–8); hence Christians need to pray for God to empower and guide them to fulfill this role. Christians need to be prayerful people; they must pray for themselves, and for the church of Christ to be faithful in her role to the society and for their protection against all evil; they must pray for God to change the hearts of sinful men in order for them to repent, believe Christ and live according to the Gospel. Christians must also pray for the rest of society (1 Timothy 2:1–7). This is the role of the Christian in the society, and it must be fulfilled for the salvation of souls, for the good of man, and ultimately for the glory of God (Titus 2—3; 1 Peter 4:7–11).