18 So He was saying, “What is the kingdom of God like, and to what shall I compare it? 19 It is like a mustard seed, which a man took and threw into his own garden; and it grew and became a tree, and the birds of the air nested in its branches.”
20 And again He said, “To what shall I compare the kingdom of God? 21 It is like leaven, which a woman took and hid in three pecks of flour until it was all leavened.”
22 And He was passing through from one city and village to another, teaching, and proceeding on His way to Jerusalem. 23 And someone said to Him, “Lord, are there just a few who are being saved?” And He said to them, 24 “Strive to enter through the narrow door; for many, I tell you, will seek to enter and will not be able. 25 Once the head of the house gets up and shuts the door, and you begin to stand outside and knock on the door, saying, ‘Lord, open up to us!’ then He will answer and say to you, ‘I do not know where you are from.’ 26 Then you will begin to say, ‘We ate and drank in Your presence, and You taught in our streets’; 27 and He will say, ‘I tell you, I do not know where you are from; depart from Me, all you evildoers.’ 28 In that place there will be weeping and gnashing of teeth when you see Abraham and Isaac and Jacob and all the prophets in the kingdom of God, but yourselves being thrown out. 29 And they will come from east and west and from north and south, and will recline at the table in the kingdom of God. 30 And behold, some are last who will be first and some are first who will be last.”
There is a contrast in these sections. In the first, Jesus compares the Kingdom of God to a very small thing that grows quite large. While in the latter, the Lord highlights that while the Kingdom will experience tremendous growth, there will be those who remain outside of it.
I’ve seen some try to read into Christ’s use of birds as a reference to Satan and leaven as a sign of corruption within the Kingdom, but that doesn’t make much sense compared to other passages. While there is certainly corruption that infiltrates the earthly kingdom of God, the central idea of both is that of expansion. The church would start as a very small thing (a core of 11 apostles and maybe a few thousand followers) and would quickly grow over the 1st century into a widespread religious force.
Now, this growth would attract many into the religion, but not everyone who joined up would be a disciple. I think one of the things we’ve drifted from in our modern Christian religion is the discipleship model. We emphasize the sinner’s prayer, church attendance, and living morally (or at least feeling really, really bad for living immorally.)
I think it’s interesting that in the latter passage, when Christ describes the dialog between the Lord of the house and those seeking entrance, that their argument boils down to, “We showed up at your synagogue, heard your lectures, and grabbed a bite to eat with you afterwards.”
In context, the Lord Jesus is speaking to an ancient Jewish audience who believed themselves favored as God’s chosen people and thus were assured of a place within the Kingdom of God. But it’s not that hard to apply it to you and I. This could easily be written as, “Hey, we went to church, said the right prayer, hung out with the right crowds, and felt really bad about sinning when we did it, so let us in.”
There is something more to Christianity. Something that we are called to strive towards and I would hazard that that is the heart and mind of Christ and His utter humility of the soul, subjecting Himself to the Incarnation and to death on a cross so that His loss would be to our benefit. It is the example set by Christ within the gospels, a life devoted to submission to God and to the care and well-being of our fellow man.
It is, in a word, discipleship and it should be what we as Christians strive towards.