The death and resurrection of Jesus Christ means that the pulpits in church buildings are not our pulpits, but they are the pulpits of Jesus Christ. Throughout His time on earth, Jesus lead a very public ministry, his death was a national matter, and his resurrection made folly of the Roman guards who were stationed outside His tomb. His ascension into heaven means that He is ruling there. As such, any ambassador who steps up onto the pulpit to declare the Word of the Lord is not doing this in a corner, but before all men under heaven and earth.
We want our language in the public square to be fitting for public discourse. Yes, Christians should be in the public square. But if you think about it, the pulpit is in the public square. From the Christian pulpit, the summons of God to all men to repent and believe goes out. We must not draw a line between the pulpit and the public square. This would be a fictional line.
Acts 1 and Matthew 28 set out the Christian Church as witnesses to the Name of Jesus Christ. We have been sent out by Jesus Christ to witness to the world. On the confession that Jesus is the Christ, Jesus is building His Church, and against that Church the gates of Hell will not prevail (Matt. 16:13-21).
Reformed Christians confess in Lord’s Day 31 of the Heidelberg Catechism that “the kingdom of heaven is opened when it is proclaimed and publicly testified…” The Son of God accomplishes three actions through His Church: “gathers, defends, and preserves for himself.” (LD 21) We also pray: “Preserve and increase your church.” (LD 48). You can find all of these references in this catechism.
When the Apostle Paul brought his testimony before Agrippa in Acts 26, he affirms that this was not done in a corner: “that the Christ must suffer and that, by being the first to rise from the dead, he would proclaim light both to our people and to the Gentiles.” (Acts 26:23). The Apostle Paul writes: “For the king knows about these things, and to him I speak boldly. For I am persuaded that none of these things has escaped his notice, for this has not been done in a corner.” (Acts 26:26)
If the death and resurrection of Jesus did not happen in a corner, then the Word of God declared on the pulpit is also message that takes place in the public square. This is no private message.