Parables of the way of God:

‘Both parables (the treasure and the yeast) state that since Jesus has come the field no longer stands empty, the dough is rising, even if the evidence is invisible or ambiguous. This statement must not be debased by being made to refer to the church that gradually wins over the majority or a Christianity silently transforming the world. Jesus is, on the one hand, exhorting his followers to preach and act unremittingly as he has taught, and on the other, apprising them that they will not appear to succeed, no matter how hard they work … until God takes a hand and consummates his Kingdom.’

Eduard Schweizer, The Good News According to Matthew, 307.