There are two aspects of Faithfulness. There is the Faithfulness of God and the fact that we are called to be Faithful.
22 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, 23 gentleness, self-control; against such things there is no law. 24 And those who belong to Christ Jesus have crucified the flesh with its passions and desires.
25 If we live by the Spirit, let us also walk by the Spirit. 26 Let us not become conceited, provoking one another, envying one another. (ESV)