Describes what is inherently good, useful, and beneficial — not merely pleasant, but morally excellent and profitable. In the NT, agathos denotes goodness rooted in God's character: 'No one is good except God alone' (Mark 10:18). It describes good works, good fruit, and the good deposit of faith.
Jesus' declaration that only God is truly agathos redefines human goodness as derivative — we are good only as we reflect God. Paul uses it to describe the works God prepared in advance for us (Ephesians 2:10) and the transformation of the renewed mind that discerns God's 'good, pleasing, and perfect will' (Romans 12:2). The 'good soil' in the parable of the sower represents hearts receptive to truth.