Matthew 6:33 KJV
But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you.
I remember being taught in Bible College that the primary application of the Sermon on the Mount is to the Jews and is an offer of the Kingdom. We of course employ many parts of that sermon to modern day Christianity;
The Lord's Model Prayer
Judge not that ye be not judged and
Seek ye first the Kingdom of God
Are all favorites of most Christians and I am not today claiming that we should not see them as having application to Christianity today. Some Christians believe this sermon to be the key to being a Christian. Those Anabaptist forefathers which eventually became the Mennonites and Amish were willing to die rather than forsake a life lived according to the Sermon's model.
But an interesting thought came to my mind as I read through the Sermon in a devotional way; could this not be the "constitution" that will be used to govern the 1000 year reign of Christ? If so, we know that we will rule and reign with Christ and that He will rule with a rod of iron. It is likely that these are the laws we will enforce in the millennium.
Once again, I am sure that there is an application for today's Christians that can be found in the Sermon on the Mount. But fresh light has been shed for me as I have envisioned those souls in the millennial kingdom needing to be reminded to pray to the Lord who is visibly before them, needing to be urged to meekness or being persecuted and literally seeing their persecutors dealt with.