Mark 4:30–34 (NKJV): 30 Then He said, “To what shall we liken the kingdom of God? Or with what parable shall we picture it? 31 It is like a mustard seed which, when it is sown on the ground, is smaller than all the seeds on earth; 32 but when it is sown, it grows up and becomes greater than all herbs, and shoots out large branches, so that the birds of the air may nest under its shade.” 33 And with many such parables He spoke the word to them as they were able to hear it. 34 But without a parable He did not speak to them. And when they were alone, He explained all things to His disciples.
So the kingdom of God begins as this tiniest of seeds and grows to be a massive entity that provides shelter for the weary.
I have heard so many claim that the church today is not what it used to be. In many ways that statement may be true, but it is not indicative of the kingdom. Despite our feelings, the world's view of Christianity, the craziness of Denominations, the lack of spirituality, or any other accusation one could make; the true kingdom of God is growing and will continue, until the Lord comes back. The kingdom is growing not by religious morality but by people saved from sin by the blood of Christ, who are growing and struggling through life by the grace of God. They are buds on the tree whose flowers bloom with the fragrance of Christ, and permeate the world with the aroma of heaven. They move through this world unnoticed for the most part. They leave no great monuments attesting to their worth or contribution to society, but obscuringly fade away into the great tapestry woven by the Master. They are the healing balm of Gilead and the perfume of the rose of Sharon.