Take care, brethren, that there not be in any one of you an evil, unbelieving heart that falls away from the living God.Hebrews 3:12(NASB)
Although miraculously redeemed from Egypt, Israel doubted God's ability to bring them into the promised land, and unbelief caused them to miss the many blessing God planned for them. They were saved that first Passover night, but lived the rest of their life in defeat.
They believed God's word, when Moses challenged Pharoah to "let my people go". They believed Him when given instructions for the first Passover meal. They believed as the angel of death passed over their homes whose lintels were smeared with blood - and they praised God, because the blood of the lamb atoned for their sin.
Having been redeemed by grace through their faith they started to doubt God's word and disobey Him. They started to murmur and mistrust God's word, and because of unbelief, lived a defeated life. They had been redeemed from Egypt, but unbelief prevented them from gaining their reward. Evil unbelief stopped them from living a triumphant life in a land of promise, where every enemies would be routed by the power of God.
The book of Hebrews is written to post-cross believers to warn against foolishly following in the footsteps of Israel, and forfeiting the opportunity to live a gloriously, victorious life that will bring with it great reward, and give honour our Father in heaven. God used Egypt as an example for our learning - that we take care, not to make the same mistakes.
Just as Israel were saved from Egypt, so we are saved from the slave-market of sin, but are warned to take care - not follow in the footsteps of those who started to murmur against God, and fell from grace. For the rest of their lives that first generation of Israelites had an evil heart of unbelief. Having been brought out from Egyptian bondage they spent the rest of their lives in failure. Redeemed but defeated.
God promised to give them a land flowing with milk and honey. He vowed to fight for them and defeat every evil enemy, but unbelief resulted in a defeated life that dishonour the Lord - until they were buried in the desert sand. And we are warned to "take care, brethren, that there is not in any one of US an evil, unbelieving heart that falls away from the living God".
Christians in this dispensation can just as easily fall from grace. Saved but defeated. Lack of trust caused God's chosen people to fall from grace and be disciplined by the Lord. Lack of faith caused them to become apostate. Doubting God's word resulted in a rebellious generation, with a tarnished testimony, that did not fulfil their mission and brought dishonour to their Redeemer, Who brought them out of slavery. And we are warned not to have the same unbelieving heart, that falls away from God.
Some use this passage as a 'proof text' to teach that salvation can be lost through an unbelieving heart - but this contradicts the clear, biblical teaching on soteriology, which dictate that salvation is by grace through faith. Some further complicate the issue by saying that Israel's promised land represents heaven at the end of our earthly journey - but again, this does not correspond to correct, contextual biblical teaching.
Israel were saved out of Egypt by God's grace because of their faith, but were not returned to Egypt because of unbelief. Similarly, Christians who are genuinely saved by God's grace through faith will not lose their salvation - but will suffer loss of a promised reward. Those that are truly redeemed by the blood of the Lamb, but live in unbelief. They are saved - yet as though by fire, and will suffer loss of reward.
We have not only been saved from the penalty of Sin (c.f. Egypt) but also from the power of sin in our lives. Having been saved, we have been given power to live by faith and gain victory over our enemies. Once saved, we are enabled to live a victorious life that honours God - so that in the ages to come, we will receive a reward for the work we have done - through the power of the Holy Ghost.
This passage was of great significance to the writer's Hebrew brethren, in those early days of the Church, who needed to take care, lest any of them had an evil, unbelieving heart which would lead them to fall away from the living God. It is also an important for Christians today that we take care not to allow doubt and unbelief to fill our heart but to but LIVE a victorious life, through the power of the Spirit.
May we take great care we do not allow unbelief to tarnish our testimony, destroy our reward and dishonour our God.
Heavenly Father, thank You for the book of Hebrews and the warnings it gives to believers, to hold fast to the truth of God's word and be careful that seeds of doubt and unbelief are not allowed to germinate and grow in our heart. Give me wisdom and discernment as I read through the whole council of Your word and guide me into all truth, as You have promised. Thank You that in Christ we can all live a victorious life to Your honour, if we trust Your word and obey Your will. I pray that You would align my thoughts to Your thoughts and my will to Your will, so I do not go astray, or fall from grace through a doubting heart, but stand fast in the evil day - this I ask in Jesus' name, AMEN.