There are two areas in which a man can be blameless. He can be blameless in his practice based upon his efforts to do right. Additionally, a believer can be blameless positionally, but this is completely based upon the finished work and righteousness of Christ. This second area of blamelessness is the subject of Ephesians 1:4 as is also the case in Colossians 1:22. In the context of that passage, it is clear this blamelessness comes only through the reconciliation of Christ (Colossians 1:21). This means that in Christ, believers bear no guilty responsibility for sins they have committed. Instead, believers are viewed and accepted in the righteousness of Christ (Ephesians 1:6).
Most people unfortunately limit the meaning of sobriety to the absence of alcohol, but scripturally speaking, the meaning involves a much broader scope. Sobriety is the opposite of being beside oneself (2 Corinthians 5:13) or mad (Acts 26:25) and is akin to being alert (1 Thessalonians 5:6). The word sober is used in conjunction with the words grave (1 Timothy 3:11; Titus 2:2) and temperate (Titus 1:8; Titus 2:2) indicating that it is accomplished when one is in control, down to earth, and finds the proper balance in his thoughts and actions. One who is sober is humble (Romans 12:3), not drunken (1 Thessalonians 5:7-8), and well aware of the circumstances surrounding him at all times (1 Thessalonians 5:6, 8; 1 Peter 5:8).
