Based on his earlier discussion, the author of the letter in Hebrews 4:11 issued a call for believers to stay focused and diligently seek to enter the promised rest. Believers, he admonished, must not emulate the bad examples of the disobedient Israelites, who had their blessings forfeited through unbelief. In verse 12, he began with the conjunction “for” to link he was saying to their earlier discussion. He was calling on them not to emulate the disobedient Israelites who defaulted on entering into the rest of God. Their failure, he surmised, was due to their disobedience to the Word of God. He wanted them to know the power of the Word of God with the hope that they would be obedient to it.
 
Here, we are shown how God’s Word can do a powerful work in the hearts of the people who will hear and allow it to expose their weaknesses; and then obey its prescription. He asserted that God sees and knows everything. He reads our very thoughts too. Hence, it would be foolhardy to disobey His life-giving and sustaining Word. To ignore it would be at the perils of entering into the certainty of judgment. So, in two verses, the writer called on his readers to be diligent to maintain a right heart for God. The reason he said was because God’s powerful Word could expose sin, and nothing could be hidden from Him.
 
Several things indicate how the Word of God is powerful. Firstly, the Word of God is living. It is current and will never go out of date. It will always speak to all issues in life. Secondly, God’s Word is active. The word “active” is translated from the same word as “energy.” It simply means that the Word of God is effectual and will accomplish the plan and will of God. Thirdly, it is sharper than any two-edged sword. It can cut deep into the core of our being. It deals with the issues of the soul and spirit.  Fourthly, it is piercing. It reaches the human conscience that remains open to God’s dealing. And finally, the Word of God is the authoritative judge of man’s thoughts and the intentions of the human heart. The “thoughts” here refer to negative emotions, such as anger and envy that a person conceals from others. The “heart” is referring to a person’s innermost being. The implication is that the Word of God can judge our innermost thoughts and feelings.
 
God’s Word would expose sin; but never for the purpose of embarrassing, but to restore that person. A person can never deal with the sins that he or she is unaware of. That’s where the Word of God comes in, to cut through the fog; and get to the heart of the matter. The Word would deal with the core of a person’s life, the thoughts, and the feelings; and reveal things that are offensive to God, thus enabling a person to repent and be restored to God.
 
In verse 13, the writer moved from discussing God’s Word to God Himself. Here, we see that God is omniscient. It is impossible to hide from God for He sees everything. The term “open” literally means “naked.” Our innermost being is ever naked and laid bare before God. Nothing is hidden from the eyes of God. The phrase, “… with whom we have to do” simply means we are accountable to God. The purpose of the writer was to have the readers align their hearts with God through faith. He wanted to show that finally, believers would have to give an account of their lives to God.  
 
There is a need to be serious with the Lord and His Word. No one can merely slide along in the faith and slip unnoticed into God’s promised rest. Why? His Word will reveal our hearts. The exhortation is for us to interact with the Word and the Lord Jesus prayerfully and thoughtfully. We will experience His gentle yet healing touch when we come to the Written and the Living Word. Without a doubt, we will experience a deep and abiding touch.