The kingdom of heaven of which Jesus spoke is the unified field of consciousness. The seeds in Jesus' parables are ideas in our consciousness. A small seed planted in the right conditions and tended in the appropriate ways can flourish. The same is true of the thoughts in our consciousness.
"Think about God and God will think about you. When we turn from destructive emotions, they are no longer fed by the creative imagination. A transformation takes place when love destroys hate by absorbing it in its Divine flame. The negative state which we have created by unhappiness cannot be healed by adding more unhappiness nor by analyzing the unhappiness we already have. Rather,it is healed as we turn to the contemplation of wholeness. Filling the consciousness with joy lifts grief out of itself until it no longer exists." -- Dr. Ernest Holmes
There is nothing between us and the Kingdom of God but our own mistakes.
What seeds are we planting? Is the field (of consciousness) ready?