To answer this question of the weakness of the flesh, we must look beyond the question of sin to the issue of faith. Faith is the basis for our relationship with God.(John 1:12, Ephesians 2:8) It is simply impossible to come into relationship with God without it.(Hebrews 11:6) Our faith is God’s supreme treasure, and our obedience to Him is the evidence that faith exists within us.

Paul talks about “the obedience of faith.”(Romans 16:26) In Romans 6:16 he tells us: “…when you present yourselves to someone as slaves for obedience, you are slaves of the one whom you obey, either of sin resulting in death, or of obedience resulting in righteousness.” Therefore, obedience is the litmus test of faith—the proof that faith exists.

In the same way, disobedience clearly reveals the presence of unbelief. In talking about the Israelites’ sin in the wilderness, the writer of Hebrews says: “And to whom did He swear that they would not enter His rest, but to those who were disobedient? So we see that they were not able to enter because of unbelief.”(Hebrews 3:18-19) Here sin and unbelief are inextricably linked.

Disobedience—sin—is born of unbelief. So when we sin, we prove that we harbor some level of unbelief in our heart. To test this hypothesis, just imagine how you would behave if Jesus, in all His glory, visibly appeared to you. Would you sin? Of course not! The last thing you would want to do is displease Him in any way. Unbelief would be totally eradicated, and therefore disobedience wouldn’t be an option at all.

Excerpted from: Free from the Power of Sin: The Keys to Growing in God in Spite of Yourself