Two Truths and an Obligation: Finding Assurance in Romans 8
A Summary of the Katy Bible Sermon “Truth and Obligation”, preached by Matt Mancini on August 9th, 2026.
If you have spent any time in the world of icebreakers, you have likely played the game "Two Truths and a Lie." It’s a simple way to get to know people by separating fact from fiction. However, as we look at Romans 8:5-13, the Apostle Paul isn't interested in games or lies. Instead, he sets before us two truths and an obligation.
Truth #1: In God’s Eyes, There are Only Two Kinds of People
We often hear sayings about there being "two kinds of people in the world"—those who work and those who watch, or those who walk into a room and say "there you are" versus those who say "here I am." Paul’s distinction, however, is far more significant: there are those who are “according to the flesh” and those who are “according to the Spirit.”
It is vital to understand that being "according to" something is not primarily about what we do, but about who we are. It is a matter of identity before it is a matter of activity. To be "according to the flesh" means a person’s fundamental nature, essence, and disposition are ruled and driven by the flesh. Conversely, to be "according to the Spirit" means that one’s life is characterized and directed by the Spirit of God.
Many have fallen into the trap of believing there is a third category: the "carnal Christian." This view suggests there are different levels of believers—some who are fully committed and others who are truly saved but still fundamentally ruled by the flesh. However, the Bible knows nothing of a "carnal Christian." Paul is not contrasting two types of believers; he is contrasting those who are spiritually alive and those who remain spiritually dead. As the text bluntly states, a mind set on the flesh is death, while a mind set on the Spirit is life and peace.
Truth #2: Having Been Justified by Faith, You are the Second Kind
The second great truth is a message of profound assurance: if you have been justified by faith, you are no longer in the flesh. You still have your flesh, but it no longer has you. Every Christian continues to battle the flesh in this life, but those battles can be won, and the greater war has already been declared a victory!
This assurance rests on a powerful reality: the Holy Spirit dwells within every single believer. There is no additional spiritual level to achieve or second experience required to receive Him. If you belong to Christ, you have His Spirit.
Paul describes the indwelling Spirit and the life He gives to our inner man (spirit) as a pledge or earnest toward our future inheritance. Just as a down payment on a house is a commitment to complete the purchase, the Spirit’s having resurrected our inner man is a guarantee that God will one day resurrect our mortal bodies also and bring us to full glory. God will finish what He started. Having been justified, you have a secure and unshakable hope of future glorification.
The Obligation: Live Like It
The transition in verse 12—"So then"—moves us from truth to responsibility. Because these things are true, we are under obligation. Paul essentially asks: "After all the flesh has done to you, what do you owe it?"
The answer is simple: nothing. The flesh has only offered empty promises that lead to sin, misery, and death. But to the Spirit, you owe everything. He has delivered you from the power of sin and given you true and eternal life.
Therefore, our calling each day is to progressively become who we are. We are called to "put to death the deeds of the body" through the power of the Spirit. This is not something we do in order to earn life; it is something we do because we have already been given life.
As the famous Puritan John Owen once said, "Be killing sin or sin will be killing you."
As you go through your daily life, remember your identity. You are not a slave to the flesh; you are a child of God, indwelt by the Holy Spirit. Set your mind on the things of the Spirit, refuse to make peace with the flesh, and walk with the confident assurance that He who began this good work in you will surely bring it to completion.