My answer to the above question is:
When Jesus commanded the apostles to preach the gospel in Mark 16:15, He didn't just command the apostles alone, the commandment was for all saved christians .
Mark 16:15
[15]And he said unto them, Go ye into all the world, and preach the gospel to every creature.
When preaching the truth of God, it must not be done in a corner, it must be done in an open place because the whole world must know about it. As christians, we should try to reach people on a greater scale like the internet to spread the gospel.
Acts 26:26
[26]For the king knoweth of these things, before whom also I speak freely: for I am persuaded that none of these things are hidden from him; for this thing was not done in a corner.
It is not evil to talk to people personally, but it is greater and better to talk to nations of people. When we are lifting high the banner of God's truth, God wants all nations of the world to gather because His salvation is open to all nations and people.
