The Bible speaks of God's giving mankind "assurance" or "faithfulness" with regard to the 2nd Coming and the Judgment by the resurrection of Christ (Acts 17:31). How does one become assured of this by the resurrection of Christ? By His promise to return to gather His children (John 14:1-4), by His giving us the Scriptures whereby we can have knowledge of Him and salvation through Him (2 Timothy 3:16-17, Romans 10:17, James 1:21), through faith which is an obedient trust in God which allows us to see the unseeable (James 1, Hebrews 11:1). That is how we have that assurance! That is how we have faithfulness! - Through the conviction that comes from our God's giving us something that no man could ever give, the Scriptures and the things taught therein.
So, is there any Biblical passages which point to one's faithfulness equaling his conviction in the Truth? Yes...
- Matthew 23:23 - The Scribes and Pharisees did the correct actions, but they lacked the faith (conviction) in their hearts to fulfill the Law.
- Mark 2:5 - Aside from the paralytic's salvation, look at the conviction of those who were willing to even tear off a roof to get their friend to the Christ! They knew that He was able to help this man, so their conviction was shown.
- Mark 4:40 - Jesus rebuked the disciples because they didn't have a deep conviction of His ability to protect them. - They didn't have pistis, translated "faithfulness" in our passage at hand for this study.
- Mark 10:52 - Bartimaeus didn't allow people to quite him, because he had conviction in the Christ!
It might be something that is somewhat elementary to state that faithfulness is derived from the conviction in the Truth of Christ. But, if we aren't convicted will we worship, evangelize, live, help in the ways that God would have us to or even be saved from our sins? Remember, a person without conviction in the cause but still acts as if he does is worse than a person who doesn't even try.