I think Bob was a Christian, he was talking about the love which Jesus taught us that's why he is telling us to give thanks and prase to the Lord(Jesus is Lord, God is LORD), so if he believed Jesus as the Lord that makes him Jesus's follower. If you listen even to other reggae singers(like Burning Spear), you'll hear them talking about God and Jesus so Rastafarian is not a religion, it is the way of living.So Bob and most rastas are Christians.