"and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father." (Philippians 2:11).
The proclamation that “Jesus Christ is Lord” is the great task of the church
Jesus the name high over all,
in hell, or earth or sky;
angels and men before it fall,
and devils fear and fly.
We don’t have to justify the claims of the gospel to the non-Christian. It is the unbeliever that needs to be justified before God, not God before the unbeliever. We are ambassadors of the Lord Christ. Note the method of apostolic evangelism. On the Day of Pentecost, Peter preached, "Therefore let all the house of Israel know assuredly that God has made this jesus, whom you crucified both Lord and Christ." (Acts 2:36). This declaration had a powerful impact, "Now when they heard this they were cut to the heart, and said, 'Men and brethren, what shall we do?'" (Acts 2:37). It is the unbeliever that is in the position of weakness. They are still in their sin and guilt, heading for a lost eternity. We preach Christ Jesus the LORD! He is the only hope for lost sinners, "there is no other name under heaven given among men by which we must be saved." (Acts 4:12).
There is not a square inch in the whole domain of human existence over which Christ, who is sovereign over all, does not cry: "Mine!" -
Let me give you one practical example of bringing the Lordship of Christ to bear upon the public sphere. It is because I believe that Jesus Christ is Lord that I have written to our MP (see here) regarding the Human Fertilisaton and Embryology Bill. Now the secularists will say that Christian principles should not intrude upon the laws of our land. But we cannot accept that there are areas of life over which Christ is not Lord. German Christians faced similar pressure to acquiesce to the onward march of National Socialism in the 1930’s. But the Confessing Churches rightly resisted the Nazification of church and society. Their Barmen Declaration states,
8.11 Jesus Christ, as he is attested for us in Holy Scripture, is the one Word of God which we have to hear and which we have to trust and obey in life and in death.
8.14 As Jesus Christ is God's assurance of the forgiveness of all our sins, so, in the same way and with the same seriousness he is also God's mighty claim upon our whole life. Through him befalls us a joyful deliverance from the godless fetters of this world for a free, grateful service to his creatures.
8.15 We reject the false doctrine, as though there were areas of our life in which we would not belong to Jesus Christ, but to other lords--areas in which we would not need justification and sanctification through him.
Now, the church is not simply to announce that Jesus Christ is Lord. She is to live as a community under the Lordship of Christ. He is head over all things for the Church. The church is not a democracy. She is a "Christocracy". Our task is to fulfil the task that he has given us in the way that he prescribes.