In Matthew 5:33-37, Jesus calls his disciples to be people of their word. “Let what you say be simply ‘yes’ or ‘no,’” Jesus says to those who have gathered around him for the Sermon on the Mount. There are no loop holes, no easy ways out. While we, like the pharisees before us, may be tempted to cheapen our word and suggest that there is a way out of doing what we’ve said, Jesus makes no such exception.

The problem is that the moment we begin to add to our words beyond a simple yes or no is that it makes way for deceit and falsity. The implication of oaths, swears, and vows, are that without them one may not be totally truthful—and God calls His people to be unswervingly committed to the truth. There are many reasons why God would want His people to be committed to the truth, what follows is the most fundamental reason of all: God is truth and we bear His image.

God is Truth

The witness of Scripture testifies to a trinitarian truthfulness. Scripture tells us that God the Father is true, Jesus is truth, and we are given the Spirit of truth.

1 | The Father is True

God the Father is the epitome of truth. God is the standard by which all things are compared. God is true and the one who sustains truth. Moses, in Numbers 23:19, writes, “God is not man, that he should lie, or a son of man, that he should change his mind.” Likewise, in James’s epistle, he writes that God is unchanging and one who is free from variation or shadows of change (1:17).

2 | Jesus is Truth

“I am the way, the truth, and the life. No one come to the Father except through me” (Jn 14:6). With these words, Jesus affirms a central reality of who He is: truth. Similarly, at the beginning of John’s gospel, he characterizes Jesus as one who is filled with “grace and truth” (1:18).

3 | The Holy Spirit is the Spirit of Truth

When Jesus ascends to the right hand of the Father, he assures the disciples that he will send his Spirit to dwell within them. In Jesus, the truth took on humanity; by the Spirit, truth indwells humanity. Jesus tells his disciples that the one whom he will send is the Spirit of truth who will guide them in all truth (Jn 16:13). In Acts 2, the Spirit descends upon the disciples and they begin to proclaim the truth—that is, the gospel—boldly and without hesitation.

This trinitarian truthfulness assures those who believe that God is true, speaks truthfully, and always does what He says He will do. If God were to go back on His word, then we would have no basis to believe that what He has spoken is true. We can always take God at His word because God’s word is always and forever true. Never has God made a promise or spoken a word that has not come to pass.

We Bear His Image

God created humanity in His image in the very beginning (Gen 1:26-27) and His people are called to be conformed to the image of the Son (Rom 8:29) by the work of the Spirit who dwells within us (Rom 8:9). As those made in the image of God, we are likewise called to know and speak truth, to live in accord with the truth. What does it look like to live in accord with the truth and integrity? It means looking a lot like what Jesus looks like in the gospels—one full of grace and truth, no matter the circumstance or the cost.

A life lived according to lies and deceit is a life not honouring the one in whose image we are made. Lies and deceit are not from God. Satan, Jesus tells us, in the “father of lies” (Jn 8:44) and through His deceit and falsehoods, sin enters the world (Gen 3) and we are consumed by it. In fact, Paul tells us that we are so consumed by it that we become slaves to sin (Rom 6) and those whose lives are marked by lies and deceit are children of Satan (Jn 8:44)

God the Father is true and speaks truth. Satan is a liar who speaks falsehoods and lives deceitfully.

When you look at your life, your words, and your actions: who’s your father?