Sermon text: Matthew 21:28-32
By this point in Matthew’s gospel, Jesus is deep in a series of tense confrontations with Jewish religious leaders. Just before this passage, they had challenged his authority, and he had turned the question back on them regarding John the Baptist’s authority—they refused to answer, so he refused to answer them. Their religious system, built on rigid tradition and personal profit, was actively blinding them to genuine faith, even as they insisted publicly on their own righteousness.
Into that context comes the parable: a father asks his first son to work in the vineyard. The son says no, but later changes his mind and goes. The father asks the second son the same thing; this son says yes, but never actually goes. Jesus’s question—”which of the two did the will of his father?”—gets an obvious answer, but then he delivers the sting: “the tax collectors and harlots enter the kingdom of God before you.” Those who had lived in open defiance to God but ultimately repented and believed were entering the kingdom ahead of religious leaders who claimed obedience but never actually delivered it.
This parable functions as a salvation parable, but it also serves as a template for ongoing obedience in the Christian life, illustrated through two men connected to Paul’s ministry.
The first son finds his real-world counterpart in John Mark. Early in his story, John Mark abandoned Paul and Barnabas partway through their first missionary journey, returning home for reasons Scripture never explains. The fallout was serious enough that Paul refused to take him on the next journey, causing a split between Paul and Barnabas—Barnabas took John Mark, Paul took Silas, and they went separate ways. That could have been the end of the story. But Barnabas, true to his name (“son of encouragement”), invested in restoring John Mark rather than writing him off. The transformation that followed was remarkable: Paul later mentions Mark warmly in Colossians and Philemon, written from prison, and in his final letter, 2 Timothy, written as Paul faced execution, he specifically requests, “Get Mark and bring him with you, for he is useful to me for ministry.” Peter, too, refers to Mark affectionately as “my son” in 1 Peter—a connection scholars believe explains why Mark’s gospel reads as Peter’s firsthand recollections of Jesus, delivered in the fast-paced, fact-focused style suited to a Roman audience. John Mark went from failure and rejection to being trusted by two of the most significant figures in the early church—a genuine turnaround from “I will not” to faithful obedience.
The second son finds his counterpart in Demas, a much less familiar name. Like Mark, Demas is mentioned alongside Paul in Colossians and Philemon, suggesting he was trusted and present during Paul’s imprisonment. But by the time Paul wrote 2 Timothy, just a few years later, everything had changed: “Demas has forsaken me, having loved this present world, and has departed for Thessalonica.” Someone once close to the inner circle abandoned Paul precisely when he needed support most, for reasons Scripture doesn’t specify—perhaps the difficulty of the work, fear of associating with a man facing execution, or simply competing priorities that eventually won out. This mirrors the parable of the sower’s description of seed among thorns: those who receive the word but let the cares of the world and the pull of material comfort choke it out, leaving them ultimately unfruitful despite an initial “yes.”
This raises an uncomfortable but necessary question: what does a “past tense Christianity” look like? Plenty of people describe their faith entirely in terms of a decision made decades ago—a specific year, a specific church, a specific baptism—without any sense of how God is actually active in their life today. That’s not a question about losing salvation, which Scripture never presents as something believers can forfeit once genuinely received; it’s a question about whether the profession was ever matched by ongoing obedience. A “yes” given once and never followed through, much like Demas, carries no more kingdom value than an outright refusal that’s never repented of.
The application lands as a personal challenge in two directions. For those functioning like the first son—having said no to something God has been nudging toward, whatever that might be—the invitation is simple: ask what God is calling toward, and act on it, since no one is guaranteed tomorrow. And for those functioning like the second son, having said yes at some point but drifted into a static, past-tense faith, genuine listening and surrender matter more than defending or justifying a settled self-image. When conviction surfaces, whether through Scripture, circumstance, or another believer’s honest question, the healthiest response isn’t self-justification but gratitude that God is still working—paired with humility rather than judgment toward others wrestling with the same tension.