Mark 4:25

If a person works hard to obtain something good, he or she normally receives other good things in addition. If a disciple pays attention to and assimilates the revelation God has given, God will increase his or her capacity to understand and appropriate more revelation. However this principle works the other way too. The person who does not use his or her ability to understand and respond to God’s revelation appropriately loses that ability. The disciples needed to use their understanding of Jesus and the kingdom by proclaiming the gospel or they would lose their ability and their understanding. This is a call for disciples to continue growing (cf. 2 Peter 3:18, the key verse of that epistle, I believe).