With all the diffferent mediums for spreading the gospel--like radio, internet and television--do we need to be careful to preserve some direct human contact with others as a part of our witness?
Absolutely. I don't think radio and internet and television can ever replace the church of Jesus Christ. They can never replace the body of Christ gathered in a local place, where people are face to face with others and participating in singing, prayer, repentance, and confession. They can't replace experiencing firsthand the assurances of pardon and the word of God being preached. I think that if all of that came only through media then the church would no longer exist as God designed it to exist.
There is something about being face to face. You can't be in a marriage that is just televised. Likewise you can't have a church that is just televised, broadcasted, or posted online.
God means for there to be a touchable aspect to the church. It says in 1 John, "we declare to you the eternal life which we have seen and which we have touched." So Christ became a human being in order to initiate centuries of touching, you might say. That is, human beings reaching out and touching the poor and touching the needy and getting their arms around them.
The embrace, the hug, the handshake; the ear, the eye: these are all physical things that are not intented to be replaced with glass screens or sound waves coming through a box. Christ means for there to be a body of people who are face to face with each other, loving each other, exhorting each other, helping each other, and getting face to face with each other--to each other and to him--in worship.