If you ever say Amen it's usually a response to what someone else has said or prayed, right?
And it's usually after what they've said, right?
And only if it's really good do you repeat it: 'Amen, Amen!', right?
So it's an affirmation that someone else has just spoken truth (Amen is straight from the Hebrew for truth).
But when Jesus comes along, what does He do? He gives Amens to His own sayings: 30 times in Matthew alone! And in John's Gospel He gives a double-Amen to 25 of His own teachings!
e.g. Amen, Amen I say to you, whoever hears my word and believes Him who sent Me has eternal life (John 5:24)
What's Jesus doing by prefacing His teaching with 'Amen, Amen'? Well let me put words to what this means. Jesus is basically saying:
"You don't stand in judgement on my word. I won't even wait for your Amen. Your Amen could only ever be the faint echo of my own Amen! You do not and cannot stand in judgement on my word. Before you've even heard a syllable of it, I tell you on my own authority that this is truth. This is the only authentication or approval these words ever could or should have - my own. This is true because I say it, not because you have some vantage point from which to assess these words. Let my Amen recalibrate everything you consider to be truth. You must simply accept my words as the gold standard of truth because it is I who speak them. In short: It doesn't matter what you think - this is the truth, deal with it!"
Who speaks like this? Only God's Faithful and True Amen (Rev 3:14).
Imagine if our bible reading, our theology, our apologetics, our Christian obedience was shaped, not by whether we thought in all good conscience we could give our Amen to Christ? What if we stopped trying to assess Christ's word with our Amens and instead simply received His Amen in glad submission?
May we hear His word in the Spirit in which it was spoken - as truth itself. (John 17:17)