The Book of Mark: The Heart of the Problem is a Problem of the Heart

Mark 4:1-20 NASB
Again He began to teach by the sea. And such a very large crowd gathered to Him that He got into a boat on the sea and sat down; and the whole crowd was by the sea on the land. 2 And He was teaching them many things in parables, and was saying to them in His teaching, 3 “Listen to this! Behold, the sower went out to sow; 4 as he was sowing, some seed fell beside the road, and the birds came and ate it up. 5 Other seed fell on the rocky ground where it did not have much soil; and immediately it sprang up because it had no depth of soil. 6 And when the sun had risen, it was scorched; and because it had no root, it withered away. 7 Other seed fell among the thorns, and the thorns came up and choked it, and it yielded no crop. 8 Other seeds fell into the good soil, and as they grew up and increased, they yielded a crop and produced thirty, sixty, and a hundred times as much.” 9 And He was saying, “He who has ears to hear, let him hear.” 10 As soon as He was alone, His followers, along with the twelve disciples, began asking Him about the parables. 11 And He was saying to them, “To you has been given the mystery of the kingdom of God, but for those who are outside, everything comes in parables, 12 so that while seeing they may see, and not perceive, and while hearing, they may hear, and not understand, otherwise they might return and it would be forgiven them.” 13 And He said to them, “Do you not understand this parable? How will you understand all the parables? 14 The sower sows the word. 15 These are the ones who are beside the road where the word is sown; and when they hear, immediately Satan comes and takes away the word which has been sown in them. 16 And in a similar way these are the ones sown with seed on the rocky places, who, when they hear the word, immediately receive it with joy; 17 and yet they have no firm root in themselves, but are only temporary; then, when affliction or persecution occurs because of the word, immediately they fall away. 18 And others are the ones sown with seed among the thorns; these are the ones who have heard the word, 19 but the worries of the world, and the deceitfulness of wealth, and the desires for other things enter and choke the word, and it becomes unfruitful. 20 And those are the ones sown with seed on the good soil;  and they hear the word and accept it and bear fruit, thirty, sixty, and a hundred times as much.”

Proverbs 4:23
Watch over your heart with all diligence, for from it flow the springs of life.

Jeremiah 17:9-10
The heart is more deceitful than all else and is desperately sick; who can understand it? 10 I, the Lord, search the heart, I test the mind, to give to each person according to his ways, according to the results of his deeds.

Romans 8:5-8
For those who are in accord with the flesh set their minds on the things of the flesh, but those who are in accord with the Spirit, the things of the Spirit. 6 For the mind set on the flesh is death, but the mind set on the Spirit is life and peace, 7 because the mind set on the flesh is hostile toward God; for it does not subject itself to the law of God, for it is not even able to do so, 8 and those who are in the flesh cannot please God.

Romans 12:2
And do not be conformed to this world, but be transformed by the renewing of your mind, so that you may prove what the will of God is, that which is good and acceptable and perfect.

2 Corinthians 10:3-6
For though we walk in the flesh, we do not wage battle according to the flesh, 4 for the weapons of our warfare are not of the flesh, but divinely powerful for the destruction of fortresses. 5 We are destroying arguments and all arrogance raised against the knowledge of God, and we are taking every thought captive to the obedience of Christ, 6 and we are ready to punish all disobedience, whenever your obedience is complete.

Genesis 6:5-6
Then the Lord saw that the wickedness of mankind was great on the earth, and that every intent of the thoughts of their hearts was only evil continually. 6 So the Lord was sorry that He had made mankind on the earth, and He was grieved in His heart.

Mark 4:13
And He said to them, “Do you not understand this parable? How will you understand all the parables?