In Mark the 4th chapter Jesus is speaking to the disciples about taking heed to what they hear, and what happens when we don't hold ourselves accountable to what we hear the LORD speaking to us.
To hear means to be able to receive communication from someone, which in turn produces a result in the one, communicated to. This is important because the LORD speaks and reveals Himself to us based on our ability to hear Him, or receive communication from Him, which should cause a response in us to do and live out that which we heard. Why this is important is because the more that we show ourselves faithful over what we have heard from the LORD, the more He is willing to speak to us.
God's willingness to speak and reveal Himself to us, is all based on our willingness to receive His communication, and to then respond or act on that which He has spoken to us through His Spirit that lives in us. As we walk in what we hear and are accountable to it, God says since I can trust you with that, let me now share this, and the more we take heed, or are alert to what He says, the more He will communicate with us. This in turn grows our faith, and the more our faith grows, the stronger we become in God, and the stronger we become in God, the more God uses us to His glory. The more God uses us to His Glory, the more lives are changed through the message of the Gospel and Kingdom that God has put in you, because you are hearing/ receiving His communication.
Now that is the positive side of it, the negative side is this, if we don't hear, what we did have we begin to lose (verse 25). So as we look at our lives some of our struggles could be a direct result of our not hearing what the LORD is saying unto us. Beloved there is good news, all one has to do is repent of lack of hearing and commit oneself to hearing from the LORD through Jesus and watch how situations, circumstances change, and make an impact for the Kingdom. Have a blessed and prosperous day in the LORD and open your ears to hear what the Spirit is saying unto the Church.