What does Mark 4:15 mean?In Mark 4:14–20, Jesus explains the spiritual meaning behind the symbolism of the parable of the sower (Mark 4:1–9). As a sower sows seeds, some lands on the hard path and is quickly eaten by birds (Mark 4:4). The birds represent Satan who steals God's truth before it gets a chance to break through the tough shell of hardened hearts. First Peter 5:8 describes Satan as a lion who doesn't just steal truth, he devours lives. Often, those lives are destroyed by lies.
In Genesis 3, Satan deceived Eve into sinning against God, resulting in the human-wide curse of an inherited sin nature. In Mark 8:32–33, Peter bends to Satan's lie that Jesus cannot die, and then tries to prevent Jesus from fulfilling His mission. In our lives, Satan's lies appear in false religions, misinterpretations of God's character, and the belief that we need worldly things more than God's Word.
In the parable of the sower, Satan snatches the gospel away before it can save lives. What could be a harvest of one hundred-times the initial investment remains a hard heart, calloused to God's love. The Pharisees and Herodians display this hard-heartedness (Mark 3:6, 22).
As with the other examples of soils, it's possible for Satan to block God's truth in one area while we accept the message in another. All of us have strengths and weaknesses; we may be very generous with our time and resources (Mark 12:41–44) but still have anxiety about spreading the gospel (Mark 13:11). God desires us to be mature in all areas of our spiritual walk (Matthew 5:48) and has given us the Bible for that purpose (2 Timothy 3:16).