Now faith is the assurance of things hoped for, the conviction of things not seen. For by it the people of old received their commendation. By faith we understand that the universe was created by the word of God, so that what is seen was not made out of things that are visible. And without faith it is impossible to please him, for whoever would draw near to God must believe that he exists and that he rewards those who seek him.
Justification by faith
A theological doctrine that had to be enunciated at the time of the Reformation.
(The Origin of the Bible: Newly Updated by F. F. Bruce, J. I. Packer, Philip W. Comfort, and Carl F. H. Henry, 2020. The Canon of the New Testament by Milton C. Fisher. Pages 67.)
Obedience of Faith
Through Jesus Christ our Lord, we have received grace and apostleship to bring about the obedience of faith for his name's sake among all the nations, including you who are called to belong to Jesus Christ. (Romans 1:-5-6)
Paul's Triad
We give thanks to God always for all of you, constantly mentioning you in our prayers, remembering before our God and Father your work of faith and labor of love and steadfastness of hope in our Lord Jesus Christ. (1 Thessalonians 1:2-3)
Their faith was a true and living faith because it a working faith, working for God and for their own salvation. We have comfort in our own faith and the faith of others when we perceive the work of faith. (Matthew Henry's Commentary on the Whole Bible: Complete and Unabridged by Hendrickson Publishers, Inc, 2003. Page 2338)