"Even so must their wives be grave, not slanderers, sober, faithful in all things." 1 Timothy 3:11
In context this verse is talking about the character of a deacon's wife. But as I read the verse, there is no doubt that it applies to us all. I mostly want to focus on the last characteristic listed-- "faithful in all things". In some versions this is translated, "trustworthy" in everything. It is interesting when you look at this portion of the verse in a concordance, the word for "faithful" is also translated: trustworthy and believer. In short, believers in Christ should be faithful/trustworthy.
When the Bible talks about being faithful and trustworthy, it is in reference to both God and man. Where man is concerned there are certain characteristics of faithfulness that we should exhibit. We should be people who keep our word. We should be reliable. We should not be double minded- people should know where we stand. We should be people that can be trusted- trusted to keep a confidence, trusted to pray for the need, trusted and faithful with business transactions, personal relationships, etc.
Where God is concerned, this interprets into believing God's word and trust in His promises. It also means that we should be faithfully carrying out His instructions, obedient to the Holy Spirit, doing the task that He has called us to without wavering, without hesitation, without complaining. The Lord, as well as people, should find us trustworthy. He should be able to trust us to believe what He says and do what He says. If we are found faithful over even the few things assigned to us, He will trust us with bigger and more responsibilities.
We can be found faithful and trustworthy before God and man as we look to the Holy Spirit to help us follow the example that Jesus left for us. "Wherefore, holy brethren, partakers of the heavenly calling, consider the Apostle and High Priest of our profession, Christ Jesus; Who was faithful to him that appointed him, as also Moses was faithful in all his house." (Hebrews 3:1,2)
Have a great day. Believers in Christ should be faithful and trustworthy before God and man.
For further reading:
1 Corinthians 4:2
1 Timothy 1:12