There are two conditions of the heart that determine our eternal destination. The condition that we do not want our heart to get into is hardened. It says in Psalm 95:7-8, “To day if ye will hear his voice, harden not your heart.” The word translated harden, qashah (kaw – shaw´) is properly translated as “to be dense” (7125). It describes the person that doesn’t heed the advice of others or refuses to be corrected.
The apostle Paul quoted this passage in Psalm 95:7-8 three times in his explanation of Christ’s work of atonement on the cross (Hebrews 3:7-8, 15, 4:7). Paul gave this instruction, “But exhort one another daily, while it is called To day, lest any of you be hardened through the deceitfulness of sin” (Hebrews 3:13). To exhort someone means to call him near or to come along side of him in order to assist him (3870).
I think it is safe to assume that a person with a hardened heart is probably a loner, a person without any real friends. What Paul was saying was that we need to stick together. When we try to handle things on our own, we are an easy target for Satan.
David said, “O God, my heart is fixed” (Psalm 108:1). The difference between a hardened heart and a fixed heart is that a fixed heart is one that is focused outward rather than inward. The person with a fixed heart realizes it’s not all about me. Another way of looking at the fixed heart is to see it as one that is certain. There is no doubt or wavering from the truth in it.
A fixed heart is one that is unchanging and unchangeable (3559). It is hard to imagine being certain of anything in a world that is constantly changing, especially today, when the speed at which things change is so noticeable.
Paul talked about the immutability of God’s counsel or advice in connection with His promise to Abraham (Hebrews 6:13-18). The Greek word translated immutable and immutability, ametathetos means unchangeable (276). Paul goes on to say, “By so much was Jesus made a surety of a better testament. And they truly were many priests, because they were not suffered to continue by reason of death: but this man, because he continueth ever, hath an unchangeable priesthood” (Hebrews 7:22-24).
I believe David’s heart was fixed because he was trusting in the Messiah, Jesus Christ. Although David lived hundreds of years before Jesus was born, the promise was still good. When Paul said that Jesus continueth ever, he was talking about time in its unbroken duration; past, present, and future (165).