But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law. (Galatians 5:22-23).
The word we're focusing on this week inside the fruit of the Spirit list is- faithfulness.
As a reminder, the fruit of the Spirit is love. All other fruit stems from that one fruit. There is one fruit of the Spirit, it isn't a plural. It's one bundle.
The Greek word in this verse for faithfulness is pistis. Helps Word Studies explains,
pístis (from 3982/peithô, "persuade, be persuaded") – properly, persuasion (be persuaded, come to trust); faith.
Faith/pistis) is always a gift from God, and never something that can be produced by people. In short, "faith" for the believer is "God's divine persuasion" – and therefore distinct from human belief (confidence), yet involving it. The Lord continuously births faith in the yielded believer so they can know what He prefers, i.e. the persuasion of His will (1 Jn 5:4).
Pistis in secular antiquity referred to a guarantee (warranty). In Scripture, faith is God's warranty, certifying that the revelation He inbirthed will come to pass.
Faith (4102/pistis) enables the believer to know God's preferred-will (cf. J. Calvin; see 2307/thelçma).
Reflection: Faith is only (exclusively) given to the redeemed. It is not a virtue that can be worked up by human effort.
Resources:
Ligonier Devotional: Goodness and Faith
Faith is another fruit of the Spirit in our lives (Gal. 5:22). But when the Apostle refers to faith, he speaks not merely of “believing in God.” Paul also calls us to “believe God.” Believing in God is not that remarkable — even demons do that. What the Lord wants is a people who trust in His promises alone (James 2:14–26).
GotQuestions: Fruit of the Spirit- What is Faithfulness?
Faithfulness is believing that God is Who He says He is and continuing in that belief despite the vagaries of life. Functionally, that means we trust what God says in the Bible, and not necessarily what the world or our own eyes tell us. We trust He will work out everything for good. We trust He will work His will in us. And we trust that our situation on earth is nothing compared to our future reward in heaven. The only way we can have such faith is by the Holy Spirit's influence. He testifies to the truth and impels us to seek God. The Spirit makes us faithful.
Arthur W. Pink:
Faith endures as seeing Him who is invisible (Heb. 11:27); endures the disappointments, the hardships, and the heart-aches of life, by recognizing that all comes from the hand of Him who is too wise to err and too loving to be unkind. But so long as we are occupied with any other object than God Himself, there will be neither rest for the heart nor peace for the mind. But when we receive all that enters our lives as from His hand, then, no matter what may be our circumstances or surroundings—whether in a hovel or prison-dungeon, or at a martyr's stake—we shall be enabled to say, " The lines are fallen unto me in pleasant places" (Ps. 16:6). But that is the language of faith, not of sight nor of sense.