faith
Now faith is the reality of what is hoped for, the proof of what is not seen. For by this our ancestors were approved. Hebrews 11:1-2
Michael Bird:
“Faith is a firm conviction that what we hope for will…happen. Faith is confidence about a future that to many observers looks futile.”
Martin Luther:
“Faith is a living, unshakeable confidence in God’s grace; [which] is so certain, that someone would die a thousand times for it. This kind of trust in and knowledge of God’s grace makes a person joyful, confident, and happy with regard to God and all creatures. This is what the Holy Spirit does, by faith.”
Karl Barth:
“Faith is trust in the divine faithfulness.”
By divine, he means the faithfulness of the Father and the Son:
Deut7:9 Know that Yahweh your God is God, the faithful God who keeps his gracious covenant loyalty for a thousand generations with those who love him and keep his commands.
1Cor1:9 God is faithful; you were called by him into fellowship with his Son, Jesus, Messiah, our Master.
Heb3:6 But Christ was faithful as a Son over his household. And we are that household if we hold on to our confidence and the hope (not our works) in which we boast.