Success in making converts doesn’t necessarily prove the truth of a religion. If it did, then Mormons and Jehovah’s Witnesses would have to be the truest forms of Christianity since they’re growing at a rate even faster than Evangelical Protestants.
Neither does a failure to make converts disprove a religion’s claim to truth either. Only a small minority of Jesus’ contemporaries accepted his message, yet this didn’t refute His messianic claims or Gospel.
Why are Evangelicals so successful in making converts? Perhaps it’s because they’re making better use of their partial truth than the Orthodox Church is with its “fullness of faith.” One might even liken it to the parable of the Good Samaritan. God revealed himself to Israel and entrusted to it His commandments. Yet in that parable, it was a Samaritan, someone regarded as defiled and outside the Covenant, who actually carried out God’s commandments, rather than through a negligent priest or Levite.
Similarly, Evangelicals are doing more with less, while we – Orthodox Christians and claimants of the “True Faith” – are doing less with more. When we wake up to this reality, we’ll also make converts – and it’s time we had. We must stop trying to be a church that will move with the world, and be the Church which will move the world!