Throughout scripture, God’s people are described as faithful. When the Lord describes the commendation the believer will receive upon entering glory, He says His words shall be, "well done, thou good and faithful servant." What is faithfulness? Here is the simplest definition. Faithfulness believes, and can be believed.
In the passive sense, faithfulness can be believed, trusted, and relied upon. Faithfulness is very predictable. You are in for no surprises with the faithful because there is a consistency of character. Remember Paul’s words, "It is required in a steward that a man be found faithful." The best example of a steward is the executor of a will. If you want your will executed properly, what do you look for in a person to do it? Talent? Genius? Charisma? In reality, nor only are those things not needed. They may be a hindrance. What you want is faithfulness! This is what God requires of all of His children. Faithfulness!
In the active sense, faithfulness believes! What do "believers" do? They believe! They believe God! They believe everything God says! If any portion of God’s Word is presented to me, and I say, "I don’t believe that", then I am an unbeliever. A believer believes all that God says. Are you faithful? Do you believe? Can you be believed? If you are a believer, the answer is yes to both of these questions. It the answer is no, what is the only conclusion that can be drawn? You are an unbeliever. Believers believe and can be believed! Lord, make me faithful!