Resisting God hardens our hearts. You may not be aware of this as you make subtle decisions that resist the Holy Spirit. Like soil erosion, having a hardened heart does not happen overnight.
The word “heart” is an important word used in the Bible and is crucial regarding our spiritual condition.
When I have a hardened heart toward God, I am distant and cold toward the Lord and am not in a relationship with Him. A hardened heart is stubborn, does not want to be molded by God, and resists the good things the Lord wants to do in our lives.
The Lord Sends Isaiah to Minister to Hardened Hearts
When Isaiah heard the call of God, something happened in his heart. He eagerly responded to the Lord. When the Lord pronounced forgiveness, Isaiah believed and no longer felt unworthy to serve in the Kingdom. Isaiah was so eager he quickly responded to the Lord and said, “Here I am. Send me.” 
While Isaiah’s heart was eager to seek the Lord and follow him, the people Isaiah would minister to had hardened hearts. Isaiah 6:9 And he said, “Yes, go, and say to this people, ‘Listen carefully, but do not understand. Watch closely, but learn nothing.’ 10 Harden the hearts of these people. Plug their ears and shut their eyes. That way, they will not see with their eyes, nor hear with their ears, nor understand with their hearts and turn to me for healing.” 
The Lord does not make people’s hearts hard, but the more they resist the truth of His word, the less they receive. As we push the Lord away, His voice becomes softer and softer until we are deaf to His calling. Drifting away from the Lord is gradual, which is why it is so dangerous.
Lord, Soften My Heart
The people Isaiah ministered to had hardened hearts, but they could have chosen a different path. It is the same for us today. What do we say when we realize we are on an empty path in life? Lord, soften my heart. Remember, it is never too late to cry to the Lord to soften your heart. Good things begin to happen when our hearts begin to soften toward God.
God may be calling you to repent of your sins. Repentance is when we turn away from our sins and turn toward God. Two thieves were crucified with Jesus, and both began the day with hardened hearts. Then something happened and one of the thief’s hearts. It began to change. Luke 23:42 Then he said, “Jesus, remember me when you come into your Kingdom.” 43 And Jesus replied, “I assure you, today you will be with me in paradise.” 
God has such beautiful things ahead for everyone who turns away from their hardened heart and toward Him. Cry out to God today in prayer and ask Him to soften your heart. Ask the Lord to help you better to hear His voice and obey. God blesses that request.
To learn how resisting God hardens our hearts, listen here:
[1-3] Tyndale House Publishers. (2015). Holy Bible: New Living Translation . Tyndale House Publishers.