The book of Mark has alot of reference about the condition of the heart. Jesus wasn't kidding around when He spoke to people. He had plenty to say about the heart.
Chapter one: we find Him starting His ministry, picking out his team, performing miraculous acts. Touching people's hearts.
Chapter two: It didn't take long for the religious leaders of the day to take notice of Him. They began to constantly question Jesus in order to trap Him in His words. When He answered them, He challenged the condition of their hearts.
Chapter three: Jesus goes to the temple where a man with a paralyzed hand was being shunned. There is pressure for him to be healed on the Sabbath, but Jesus saw through their plot and addressed the hardness of their hearts.
Chapter four: The familiar story of the seed being sown. It may not say it directly, but we do understand that the seed of the Word will grow in a tender heart.
Chapter six: The disciples saw Jesus walking on the sea during a storm. He calmes the waves and gets on the ship with them. They were astonished but "their hearts had become dull and lost the power to understand".
Chapter seven: There were strict rules about what you could and could not eat. Traditions of religion did not determine who was unclean. He addressed the condition of the heart.
Chapter eight: Jesus and His team were travelling by boat. There wasn't enough food brought along for them to eat. Even though He had fed multitudes with little, they had already forgotten about it. Jesus addressed the hardness of their hearts.
Chapter nine: A boy is possessed and his dad cries out to Jesus for help. He also admits that his faith is there but unbelief also exists. These things are seated in your heart.
Chapter ten: Jesus was asked about divorce. There were laws in place that would give permission to divorce over a burnt dinner. Putting away a partner over petty matters is wrong. Instead, He addressed the issue of their hearts.
Chapter ten: The rich, young ruler asked Jesus about getting into the Kingdom. When he admitted to keeping the law of the prophets, Jesus asked him to reflect on his heart. Could he give up all his wealth and not rely on the things of this world to save him? It is a reflection of the heart...an analyzation of where his true dependance was.
Chapter eleven: Most importantly, forgiveness is the topic of the moment. If we cannot forgive, then the matter of our spiritual forgiveness is in danger. This is a matter of the heart's condition.
Do you believe in Jesus? You are no better than the demons who believe in Him and tremble. Have you reflected on your heart's condition? Have you forgiven others? What do you rely on for your salvation? In these times, we are concerned about the prices of things, the status of our jobs, the sources of our incomes, the future of our finances. If this is the focus of the heart, where does our love for our God fit in that? We are to examine the reflections of our heart.