The believer must also be careful that he does not take a light attitude toward sin. He dare not use the grace of God as a license to sin. The answer is an emphatic negative. Paul knew and taught that continued sin will adversely affect a believer's faith, and faith is the very thing that makes a relationship with God possible. Continued sin becomes presumptuous, high-handed, and is evidence of rebellion.
Rebellion is the opposite of the trust and obedience of faith.
These repeated warnings are meaningful only when it is recognized that the loss of faith means the eternal loss of the soul. Sin and unbelief are closely related. The writer warned the brethren against unbelief which will lead to a departure from the living God. He mentioned the deceitfulness of sin as the cause of unbelief and reminded them that we are partakers of Christ only if we hold the beginning of our confidence unto the end. Standing in Christ is by faith.