Truth is, however, the size and scope of his memorial on the National Mall is due to one thing. He kept the union together. I pondered that awhile back (here) after visiting Springfield and it's on my mind again after being in DC and also because I'm thinking of the difficulty we seem to have in churches sometimes. Where so much more is at stake.
Jesus made at least two statements that define how the world would see Christians when our light is shining as it should. The first is known as the New Commandment--to love one another as He loved us. He said the world would see that and know we are His (John 13:34-35). I just have to believe that a noticeable (by the world) love is one that will stay together through thick and thin, working out our difficulties, loving each other even, and especially, when it's hard.
The second is when Jesus prayed for us in John 17. Seems we are to be "one" as He and the Father are one (v. 21). And, again, the world will take note...and believe. Yes, a lot's at stake. Maybe even especially the hearts of those who don't yet believe. They are watching.