The story of humankind is one of unfaithfulness to God. Abraham begins Israel's story well, but it too becomes one of unfaithfulness to YHWH. Jesus comes and lives the life of faithfulness for all humanity, so that we can now have a new start in him, so that we can now be faithful as God's new humanity in Jesus (Romans 3, 5).
Faithfulness is a fruit of the Spirit (Galatians). It is also an important part of the characteristics of love (1 Corinthians 13:4-8a). Habakkuk 2:4 informs us that in contrast to "he" who "is puffed up...the righteous will live by their faithfulness." (TNIV)
God works to ingrain faithfulness as the warp and woof of who we are. Not some spectacular fireworks in doing mighty feats for God. Sure, there can be a time and place for that for a few. But what is to make up the everyday, every week, every month and every year experience of the Jesus follower? Faithfulness is at the heart of it. Certainly in faith expressing itself through love (Galatians).
I have noticed that the people who seem the most ordinary are often the most inspiring examples, because of their faithfulness. Remember, the church of Philadelphia in Revelation 3 had only little strength. But they kept Jesus' word and did not deny his name. Jesus had no rebuke for them, but words of encouragment, promise and exhortation to hold on to what they had.
Faithfulness includes the full gamut of the Christian life. Ongoing worship, confession of sin, thankfulness, and devotion to Scripture and prayer. Devotion to one's Jesus community, to doing good to others -especially those in need. Sharing our faith by deeds and words.
There's a sameness to faithfulness. But there's also growth involved. God will be sure of that, if we're seeking to be faithful to him.
Father, Let our lives be more and more characterized by faithfulness. Through all the ups and downs of life. That we would have an ear and heart to keep following you. Through the trials. And getting back on track when we do get off. Make us more and more like your Son. By your Spirit. Amen.