Many think Saving Faith (in Christ alone without works or law) is a "free ticket to sin". Apostle Paul uses two very powerful truths and examples about our new life as believers to show why this type of thinking is very wrong.
In the first example he shows, by Baptism, how we are made one with Christ in our Spirit, not only giving us eternal life but also a quickened life. A quickened life, he shows, kills our old man (the soul with a dead spirit) and gives us a New Man in it's place (the soul with a living human spirit fused in unity with Christ's Spirit). This new life naturally changes our desires.
In the second example he shows our employment has changed. We have a new boss and economy. Our old man earned wages from sin unto death (temporary gratification but eternal damnation) but the New man can only receive rewards unto eternity (fruit unto righteousness). The old man's wages remain in the corrupted flesh and will pass away but the rewards of rigtiousenes last into eternity.
Paul then shows that is is the believer who then has the choice to continue to work for an old boss who can pay nothing or to grow fruit unto rigtiousenes that can have eternal rewards beyond a temporary life of sin.
(Preached Sunday morning, 12-19-2021, by Pastor John Young, at Maranatha Bible Baptist Church, 16990 S 38th St, Mendon, MI 49072, Between Fulton and Menden in Wakeshma Township, Near Kalamazoo and Battle Creek in South West Michigan, https://www.facebook.com/MbbcFulton)