The way you phrase this particular statement really makes my head spin.
That is what I meant when I talk about going on mental gymnastics.
Sorry for not being clear. To give some examples, someone could obey God's law because they want to look pious, because they want to earn their righteousness, they want to boast, they want to avoid hell, they want to express their faith, they want to express their love, they want to build godly character, they want to grow in a relationship with God, they want to bring about the restoration of the word, and so forth. Some of those are correct reasons that the Bible speaks in favor of while other are incorrect reasons that the Bible speaks against, so what is said against the incorrect reasons should not be mistaken as being against the correct reasons.
Here are some verses that speak against earning our salvation/justification/eternal life as a wage: Ephesians 2:8-9, Romans 3:28, Romans 4:5, Galatians 2:21, and Titus 3:5.
Here are some verses that speak in favor of our salvation/justification/eternal life requiring us to choose to be doers of the law: Ephesians 2:10, Romans 2:6-7, Romans 2:13, Romans 3:31, Romans 6:19-23, Matthew 7:21-23, Matthew 19:17, Luke 10:25-28, Titus 2:11-14, Hebrews 5:9, and Revelation 22:14.
Those are by no means exhaustive lists, but in order to reconcile them, it is clear that there must be correct reasons for why we need to choose to be doers of the law, which is not in order to earn it as a wage. Our faith upholds God's law (Romas 3:31), so faith is a correct reason for why our salvation requires us to choose to obey it, which has nothing to do with incorrect reasons of boasting in ourselves or with trying to earn our salvation as a wage.