Interesting video. I'm glad the atheist at least appreciated what the Christian was attempting to do and his polite approach. I agree that this is a good example for voluntarists to follow. It's interesting, we are studying witnessing in Sabbath school. (The SDA equivalent of Sunday school). This past weeks lesson was about sharing the Word and that while nature does show God's handiwork, you won't get any results from talking about nature alone. As Paul discovered after mixed results discussing philosophy on Mars Hill, the best thing to do it share "Christ and Him crucified." Talk about your personal testimony and relate it to the Bible. And there are many pro liberty passages in the Bible. Here are my two favorites that mirror each other.
Jeremiah 31:31-34,Hebrews 8:8-12
31 Behold, the days come, saith the Lord, that I will make a new covenant with the house of Israel, and with the house of Judah:
32 Not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt; which my covenant they brake, although I was an husband unto them, saith the Lord:
33 But this shall be the covenant that I will make with the house of Israel; After those days, saith the Lord, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.
34 And they shall teach no more every man his neighbour, and every man his brother, saying, Know the Lord: for they shall all know me, from the least of them unto the greatest of them, saith the Lord: for I will forgive their iniquity, and I will remember their sin no more.
8 For finding fault with them, he saith, Behold, the days come, saith the Lord, when I will make a new covenant with the house of Israel and with the house of Judah:
9 Not according to the covenant that I made with their fathers in the day when I took them by the hand to lead them out of the land of Egypt; because they continued not in my covenant, and I regarded them not, saith the Lord.
10 For this is the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people:
11 And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest.
12 For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more.
The same passage found in the Old and New Testament where God promises a new covenant where law is "written in the heart" and so people are moral from the inside and opposed to morality being forced from the outside. A truly moral people need no external laws. You don't need, for example, a law saying "It's illegal to steal" in a moral society. Nobody will want to take what doesn't belong to him, and nobody would feel the "need" to steal because anyone who had extra wouldn't sit back and let someone else starve. And you wouldn't have to worry about freeloaders because nobody would want to just sit back and receive a handout because that isn't moral either.