by 
The day is coming when we will be fully like Jesus, who spoke truth in His heart throughout His life and who speaks truth in His heart even to this day.
We know, of course, that that person is Jesus Christ. He was obedient to God and spoke truth in His heart. That’s because He was—and is—the truth.
What would it mean to speak truth, not just from our hearts, but in our hearts? What would it mean to follow Jesus down this road of truth-speaking? Let me give three thoughts.
Know the Truth
Speaking the truth in our hearts requires that we know the truth. Jesus grew up knowing and studying the Scriptures. He referenced them throughout His earthly ministry, and He clung to them in hope. We also should know the Scriptures. We are tempted every day to express cynicism about our lives, our families, our churches, and our workplaces. “I will never change. God created me with a short temper.” “My work doesn’t amount to anything. It’s worthless.” “The church is full of hypocrites.” All lies. All of these thoughts, often harbored in our hearts, have corresponding true statements in Scripture. In regard to a short temper, there is the truth that patience is a fruit of God’s Spirit in us and that God is making us holier (Gal. 5:22; Heb. 12:10). In regard to a seemingly irrelevant job, there is the truth that we ultimately work unto Christ—there is no irrelevant work (Col. 3:23–24). In regard to the hypocrisy of the church, there is the truth that the church exhibits sinfulness, but it is holy and growing up into Christ her Head (1 Cor. 5:1–2; Eph. 4). Jesus prayed that His disciples would be sanctified in the truth: “Your word is truth” (John 17:17). Know the truth so that the lies you tell yourself have an antidote.
Trust the Truth
Speaking the truth in our hearts requires that we actually trust the truth. When we hear lies in our hearts and are tempted to believe them, we have to make an active decision to choose the truth rather than lies. This can be hard. Jesus, in the wilderness before His public ministry began, chose the truth over and over again in the face of Satan’s lies (Matt. 4). He remembered what God had said, and He chose to believe it. We must actively choose to believe God’s promises when we face the cynicism that I noted above. And, because we are sinners (unlike Christ), there is a further way in which we must trust the truth. We must choose to trust the truth in the midst of our sin. For example, we have all been tempted in the heat of an argument to believe that we are completely in the right, even though we know in our heart that we have sinned against the other person, whether they be a spouse, coworker, or friend. In such a situation, admit to yourself in your heart what is true. “I have sinned by presuming motives.” “I have sinned by reacting too harshly.” We have to realize things ourselves before we can be honest with our opponent and seek healing.
Do the Truth
Speaking the truth in our hearts requires that the truth we know and trust be externalized in our words and actions. Jesus was sinless because His heart was sinless. The truth in His heart made its way into His words and deeds. When James tells us not to be only hearers of the Word, but also doers (1:22–25), I imagine that he has this paradigm of Christ in mind. For example, Ephesians 4:32 says, “Be kind to one another, tenderhearted, forgiving one another, as God in Christ forgave you.” This simple admonition is grounded in a truth that we know: God has forgiven us. It then propels us on to live that truth out in our lives. Because Christ has forgiven us, we should do certain things. On the other hand, if we believe lies, we are compelled to do other things. For example, if we believe the lie about the hopeless hypocrisy of the church, we are bound to act out of that lie. We are bound to engage in gossip. We are bound to undermine others. We are eventually bound to leave the faith. On the contrary, if we believe the truth that sin is a reality in the church in this age, we will be sober minded about sinfulness. If we believe that we are a holy nation bound for the new Jerusalem, we will express hope about the future (1 Peter 2:5; Rev. 21). We won’t give up. We’ll build up others. We’ll keep showing up.
I long for the day when I will stop speaking lies in my heart but instead always speak the truth. It is hard to imagine a life in which there is not always internal conflict within myself between what is right and wrong, between what is true and false. But we know the day is coming when we will be fully like Jesus, who spoke truth in His heart throughout His life and who speaks truth in His heart even to this day. “We shall not all sleep, but we shall all be changed, in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised imperishable, and we shall be changed” (1 Cor. 15:51–52).