Luke 17:5-6 5 The apostles said to the Lord, “Increase our faith!” 6 And the Lord said, “If you had faith like a grain of mustard seed, you could say to this mulberry tree, ‘Be uprooted and planted in the sea,’ and it would obey you.
Hebrews 11:1-3 (Darby) 1 Now faith is [the] substantiating of things hoped for, [the] conviction of things not seen. 2 For in [the power of] this the elders have obtained testimony. 3 By faith we apprehend that the worlds were framed by [the] word of God, so that that which is seen should not take its origin from things which appear.
Matthew 14: 26-33 26 But when the disciples saw him walking on the sea, they were terrified, and said, “It is a ghost!” and they cried out in fear. 27 But immediately Jesus spoke to them, saying, “Take heart; it is I. Do not be afraid.” 28 And Peter answered him, “Lord, if it is you, command me to come to you on the water.” 29 He said, “Come.” So Peter got out of the boat and walked on the water and came to Jesus. 30 But when he saw the wind, he was afraid, and beginning to sink he cried out, “Lord, save me.” 31 Jesus immediately reached out his hand and took hold of him, saying to him, “O you of little faith, why did you doubt?” 32 And when they got into the boat, the wind ceased. 33 And those in the boat worshiped him, saying, “Truly you are the Son of God.”
James 1:6 1 But let him ask in faith, with no doubting, for the one who doubts is like a wave of the sea that is driven and tossed by the wind.
Acts 3:1-16 1 Now Peter and John were going up to the temple at the hour of prayer, the ninth hour. 2 And a man lame from birth was being carried, whom they laid daily at the gate of the temple that is called the Beautiful Gate to ask alms of those entering the temple. 3 Seeing Peter and John about to go into the temple, he asked to receive alms. 4 And Peter directed his gaze at him, as did John, and said, “Look at us.” 5 And he fixed his attention on them, expecting to receive something from them. 6 But Peter said, “I have no silver and gold, but what I do have I give to you. In the name of Jesus Christ of Nazareth, rise up and walk!” 7 And he took him by the right hand and raised him up, and immediately his feet and ankles were made strong. 8 And leaping up he stood and began to walk, and entered the temple with them, walking and leaping and praising God. 9 And all the people saw him walking and praising God, 10 and recognized him as the one who sat at the Beautiful Gate of the temple, asking for alms. And they were filled with wonder and amazement at what had happened to him. 11 While he clung to Peter and John, all the people, utterly astounded, ran together to them in the portico called Solomon's. 12 And when Peter saw it he addressed the people: “Men of Israel, why do you wonder at this, or why do you stare at us, as though by our own power or piety we have made him walk? 13 The God of Abraham, the God of Isaac, and the God of Jacob, the God of our fathers, glorified his servant Jesus, whom you delivered over and denied in the presence of Pilate, when he had decided to release him. 14 But you denied the Holy and Righteous One, and asked for a murderer to be granted to you, 15 and you killed the Author of life, whom God raised from the dead. To this we are witnesses. 16 And his name—by faith in his name—has made this man strong whom you see and know, and the faith that is through Jesus has given the man this perfect health in the presence of you all.
Acts 9:10-18 10 Now there was a disciple at Damascus named Ananias. The Lord said to him in a vision, “Ananias.” And he said, “Here I am, Lord.” 11 And the Lord said to him, “Rise and go to the street called Straight, and at the house of Judas look for a man of Tarsus named Saul, for behold, he is praying, 12 and he has seen in a vision a man named Ananias come in and lay his hands on him so that he might regain his sight.” 13 But Ananias answered, “Lord, I have heard from many about this man, how much evil he has done to your saints at Jerusalem. 14 And here he has authority from the chief priests to bind all who call on your name.” 15 But the Lord said to him, “Go, for he is a chosen instrument of mine to carry my name before the Gentiles and kings and the children of Israel. 16 For I will show him how much he must suffer for the sake of my name.” 17 So Ananias departed and entered the house. And laying his hands on him he said, “Brother Saul, the Lord Jesus who appeared to you on the road by which you came has sent me so that you may regain your sight and be filled with the Holy Spirit.” 18 And immediately something like scales fell from his eyes, and he regained his sight. Then he rose and was baptized;
Acts 14:8-10 8 Now at Lystra there was a man sitting who could not use his feet. He was crippled from birth and had never walked. 9 He listened to Paul speaking. And Paul, looking intently at him and seeing that he had faith to be made well, 10 said in a loud voice, “Stand upright on your feet.” And he sprang up and began walking.
Hebrews 11 (Darby) 1 Now faith is [the] substantiating of things hoped for, [the] conviction of things not seen. 2 For in [the power of] this the elders have obtained testimony. 3 By faith we apprehend that the worlds were framed by [the] word of God, so that that which is seen should not take its origin from things which appear.
Verse 1: DEFINITION
The word for “assurance” or “substance” in most translations should be something like "substantiation" because the root word is from a verb not a noun.
Faith is a substantiating action. It manifests "things hoped for".