We Christians talk a lot about the “great exchange” of substitutionary atonement, and rightfully so. No concept of the gospel is more core than to realize that Jesus took the wrath of God due us and in exchange gave us his own perfect righteousness.

 But there is another great exchange that is key to one’s reception of the gospel. This exchange determines whether that other exchange ever happens for an individual. Paul talks about this other exchange in Rm 1. In fact, he talks about several exchanges that seem centered on one in particular: “They exchanged the truth of God for a lie” (v.25).

 It is important to realize this exchange happens in the heart. This word is used in two key statements by Paul, one in v.21 and one in v.24. It translates a Greek term that refers to a coalition of mind, will, and emotion. This means the exchange of the truth for a lie is more than mental. It is a blend of wrong thinking, wrong deciding, and wrong wanting. Naturally, this coalition leads to wrongdoing.

 This reality is being not only expressed but held forth as the highest value in our culture today. Everyone is being encouraged to “live out your truth.” Pop culture is peddling this value. The universities are providing doctrinal frameworks to ensure it. You might be surprised at how strongly the administrative powers of public education are pushing it, even down to the preschool levels. Value systems have been replaced. The most important thing to teach a kindergartener now is not A-B-C or 1-2-3 but that everyone should be free to be their “authentic self.” Chaos and perversion are the logical outcomes, and we are seeing plenty of these!

 When we attempt to proclaim the gospel to someone in word and deed, we do well to realize that they have already made this terrible exchange. They have exchanged the truth for a lie, the priceless for the worthless. Deep down, they probably realize their own “truth” is not working. Most will double down, moving farther away from God’s truth, trying desperately to tweak their own truth until it seems to work.

Paul paints a vivid picture of our own moment. This terrible exchange of the truth of God for a lie leads to others. Those who reject God’s truth also exchange “the glory of the immortal God for images resembling mortal man” and other creatures (v.23). This is idolatry, or false worship, and it is everywhere in a culture expressing “my truth.” Because of this idolatry, God delivers people over to unnatural passions and behaviors – another terrible exchange (vv.26-27). Of course, this isn’t new to the world, but it is certainly playing out in a dramatic scale today. Because of idolatry people have been turned over to a corrupt heart, and their lifestyles follow suit (vv.28-32).

 The point is that we Christians help nothing if we go on crusades to “reclaim” our culture and bring the pagans back in line. We, most of all, should understand that we are powerless to overturn darkened and corrupt hearts. After all, we couldn’t do it for ourselves. That was and is the Spirit’s work. All we did (and continue to do) is quit saying “no” to him and started saying “yes.” Only then was our thinking, deciding, and wanting transformed, as it continues to be so (Rm 12:2).

 We speak the truth, sure. We call sin “sin.” But our mission is to proclaim the gospel. That is the only power that brings salvation (Rm 1:16). It saves by revealing God’s righteousness (v.17). We can’t convince people of the truth. We can’t ultimately compel them to believe or to live by it. We can only be bold in proclaiming it.

 The cost of faithful gospel proclamation is going up. To not be ashamed of the gospel (v.16) is to refuse to back off proclaiming Christ. Gospel-oriented living will naturally cause us Christians to stand out in contrast to our culture. The pressures will increase, but we have one job: testify about Jesus. It is not to hammer the sinners, but to lovingly proclaim the gospel. It does the work. The Spirit brings to life. We testify, and we pray that the Spirit will win over the hearts of the lost to these two great exchanges. If they are willing to exchange their “own truth” for the truth of God, then God will exchange the righteousness of Jesus Christ for their own sin.