I have written to you, fathers, because you know him who is from the beginning. I have written to you, young men, because you are strong, and the word of God remains in you, and you have overcome the evil one.

 Here are the Christian criteria of truth. There is an external test. All teaching must be in accordance with the tradition handed down to us in Scripture and in the Church. There is an internal test. All teaching must undergo the test of the Holy Spirit witnessing within our hearts. 