Danger of hardening the heart

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Hebrews 3: 7-19
The heart is an important organ that enhances the existence of the whole body and sustains life. Cutting off some other organs of the human body may not terminate life. But when the heart is cut off, infected with disease or ceases to function, this will lead to definite end of the life of such a person. As it is with the physical body, so it is with our spiritual being. Allowing our hearts to be hardened might lead to spiritual death. Hence, the Holy Ghost counsels and cautions us thus: "Wherefore, as the Holy Ghost saith, today if ye will hear his voice, Harden not your hearts, as in the provocation, in the day of temptation in the wilderness" (verses 7, 8).
The Holy Spirit is Omniscient. From experience with the Old Testament, the writer percieves the possibility of contemporary believers hardening their hearts. On the other hand, He can see all the activities of Satan against the Church and counsels against the Church and counsels against hardening of heart. It will be wise on our part, whose minds are made up to get to heaven, to heed the warning of the Ho;y Spirit.

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COUNSEL AGAINST HARDNESS OF HEART
Hebrews 3: 7-10; Psalm 95: 7-9; 78: 18,19; Exodus 16: 2,3; Numbers 14:22,23; 1 Corinthians 10:7-11
The Holy Ghost is given to us for divine guidance. In the later ministry of Christ on earth before His crucifixion, He promised us the Holy Spirit. He revealed that when He is come, "he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come" (John 16:13). Through the Holy Spirit, the early church was built, instructed and made strong. For the continuity and stability of the Church, the Holy Spirit counsels her on the subject of hardness of heart.
Satan does not give up on any believer until he is out of the world. He keeps on contending with him through one means or the other. He employs his wiles, deploys his workers and disposes his weapon to track down Christ's faithfuls. He shoots different arrows into their hearts trying to take pssession of it. He knows that issues of life are in the heart. He tries to influence a saved soul through evil thoughts and imaginations (Genesis 6:5). He seeks to make man lose that precious salvation he got freely through Christ; lose his position in Him and his place in heaven. He also encourages disobedience to the word of God and doubt about the realityof God's promises. For these reasons comes the counsel of the Holy Ghost.
From the example of the israelites in the wilderness, we can draw out some of the ways hardness of heart sets in. Israel allowed the influence of the mixed multitude to affect them. Since the mixed multitude did not have the foundation of the fear and faith in God, they could not walk with God. Instead, they doubted God and murmured. They influenced the Israelites to murmur. Through these, their hearts became hardened. Saved people are warned against unequal yoke with unbelievers. When Christians keep close association with the unsaved and half baked believers, they will begin to learn their ways, languages, actions and reactions. There will be gradual downward journey into murmuring, complaining and disobedience. Their hearts will begin to get hardened as they select what instruction of the Lord to obey.
Israel soon forgot all the wonders of God in the land of Egypt and at the Red sea. These wonders have helped them to exhibit faith in God when they had need of food and water; they despised the unfailing power and sufficiency of God and doubted Him. This wrecked their faith and wrought hardness in their hearts. As the Holy Ghost cautioned the New Testament believers against hardness of heart, the writer reminded the Hebrew Christians of how their " fathers tempted me, proved [Him], and saw [His] works forty years" (verse 9). Hardness of heart sets in when believers who have experienced the mercy, grace and power of God allow fear and faithfulness amidst challenges of life.
A person's heart becomes hardened when he backslides and delays to return to God. Refusal to understand God's ways will lead to hardness of heart. In our walk with God, we have to understand the way God deals with His people. Sometimes, things happen, which God allows to prove our love. Some are allowed by Him to prepare us for greater experience and ministry. We also face persecution from Satan and his agents, which is part of our calling. At these times, there are believers who get offended and become impatient with God. They manifest unchristian characters which lead to hardness of their hearts. Others outrightly tempt God and incur the wrath of God.