So, you're contending God isn't strong enough to convict marlowe by that verse alone? - every word is God given, the power of Him - inside of each and every bit
.......even the demon spirits recognized Scripture
Taking verses out of context is a dangerous thing to do. It can lead to error. The verses are not each stand-alone little nuggets of Truth. Too many people think that they can just string together scriptures and arrive at Truth. Doesn't work that way.
so the Catholic magisterium now comes into play?
Understanding the historical setting of a scripture is critical; however, in a "preaching" situation any scripture must go through a transvaluation process to be relevant to us today. John was speaking to a particular group, not us. Today, the Holy Spirit speaks to us, calling us to follow Jesus, and a clergy or other person may use a scripture to reflect that present activity of God in a particular situation if it reflects the activity of God now. Clergy regularly do this - it is called preaching!