This question could be taken two different ways.
During the time of the Reformation, there were the Protestants (Lutheran and Reformed) and the Roman Catholics. But people often forget about a third group: the Anabaptists. The Anabaptists have sometimes been called the “Radical Reformers.” They received that name, not because they were extreme, but because they wanted to go back to the roots of the Christian faith. The Latin word for root is ‘radix,’ from whence we get the English word ‘radical.’ The Anabaptists wanted a simple, apostolic form of Christianity, without all the encumbrances of creeds, councils, and traditions. They wanted to start over – which is why they’re also sometimes called Restitutionists.
Should our Christianity be radical in this sense? We certainly want our Christian faith to be consistent with what the apostles taught and practiced, as revealed in Scripture. However, we shouldn’t pretend that 2000 years of NT church history have never happened. It would be foolish to ignore the precise doctrinal formulations that came out of struggles over the doctrine of the Trinity and the person of Christ in the patristic Church. It’s no wonder that Anabaptists like Menno Simons, Melchior Hoffman, and Michael Servetus ended up in Christological or Trinitarian heresies. Their radical Christianity threw the baby out with the bathwater.
But I think what my parishioner is asking is how far-reaching or extreme our Christianity should be. In that sense, I would say that our Christianity should be as radical as what the Bible says it should be. When it comes to any “should” or “ought” question in our lives, it always comes down to this question: what does God say about it in his Word?
When it comes to what we believe as Christians, we’re to believe everything contained in God’s Word. After all, it is God’s Word, inspired by the Holy Spirit. It is all God’s Word – “all Scripture is breathed out by God” (2 Tim. 3:16). The Bible is God’s pure and unvarnished truth (Ps. 12:6). If we’re to believe in God, we must also believe everything he says in the Bible, including and especially everything the gospel promises us. Having said that, we recognize that the Bible needs to be interpreted according to context and genre. For example, Satan’s words are recorded in several places in the Bible. Am I to believe that his words are true? No, for “he is a liar and the father of lies” (John 8:44). But I am to believe that the Bible gives me an accurate record of his lies.
With respect to how we live as Christians, we’re to conform our lives to everything taught in God’s Word. God’s moral law is the standard by which we seek to live. God’s moral law shapes our response of love and gratitude to God for what he’s freely given us in the Saviour. Scripture doesn’t give us leave to pick and choose which commandments we’ll obey. Our Lord said in John 14:15, “If you love me, you will keep my commandments.” And 1 John 5:3 echoes Christ’s words, “For this is the love of God, that we keep his commandments.” The Psalmist says in Psalm 119:172, “…all your commandments are right.” Ultimately, that’s pointing to our Saviour’s full-life embrace of God’s moral law.
Jesus believed everything contained in the Scriptures and he lived flawlessly according to all God’s commandments. He did this in our place, as part of his active obedience leading to our being declared righteous by God. What’s more though, if we’re united to him, and if we’re his disciples, we’re meant to be like him (Luke 6:40). We aspire to be like him. If Christ acknowledged God in all his ways by following his Word exhaustively (Prov. 3:6), then I want to acknowledge God in all my ways by following his Word exhaustively. If, in that sense, Jesus had a radical faith, I want to have a radical faith too. I want nothing less than to be like my Master.
Before he ascended into heaven, Christ gave the Great Commission to his church. The heart of the Great Commission is to “make disciples of all nations.” We’re to do that by “teaching them to observe all” that Christ has commanded. Note the word ‘all.’ The faith which we both embrace for ourselves and transmit to others must therefore be far-reaching, as far-reaching as the Bible. If someone wants to say that’s “extreme” or “radical” in a negative sense, so be it. The gospel leads us to love Christ so much that we would put him before even father, mother, son, or daughter (Matt. 10:37). He is everything to us and so the words of any naysayers mean nothing to us.