What is faith?

Hebrews 11:1-3,6 (NLT):
"Faith is the confidence that what we hope for will actually happen; it gives us assurance about things we cannot see. 2 Through their faith, the people in days of old earned a good reputation. 3 By faith we understand that the entire universe was formed at God's command, that what we now see did not come from anything that can be seen.

6 And it is impossible to please God without faith. Anyone who wants to come to him must believe that God exists and that he rewards those who sincerely seek him."

Luke 18:8 (NLT):
".....But when the Son of Man returns, how many will he find on the earth who have faith?"

There is a difference between a saving faith (evidenced by good works/obedience to God) and a dead faith (shared by demons).

James 2:14-26 (NLT):
"What good is it, dear brothers and sisters, if you say you have faith but don’t show it by your actions? Can that kind of faith save anyone? 15 Suppose you see a brother or sister who has no food or clothing, 16 and you say, “Good-bye and have a good day; stay warm and eat well”—but then you don’t give that person any food or clothing. What good does that do?

17 So you see, faith by itself isn’t enough. Unless it produces good deeds, it is dead and useless.

18 Now someone may argue, “Some people have faith; others have good deeds.” But I say, “How can you show me your faith if you don’t have good deeds? I will show you my faith by my good deeds.”

19 You say you have faith, for you believe that there is one God. Good for you! Even the demons believe this, and they tremble in terror. 20 How foolish! Can’t you see that faith without good deeds is useless?

21 Don’t you remember that our ancestor Abraham was shown to be right with God by his actions when he offered his son Isaac on the altar? 22 You see, his faith and his actions worked together. His actions made his faith complete. 23 And so it happened just as the Scriptures say: “Abraham believed God, and God counted him as righteous because of his faith.” He was even called the friend of God. 24 So you see, we are shown to be right with God by what we do, not by faith alone.

25 Rahab the prostitute is another example. She was shown to be right with God by her actions when she hid those messengers and sent them safely away by a different road. 26 Just as the body is dead without breath, so also faith is dead without good works."

Acts 20:21 (NLT):
"I have had one message for Jews and Greeks alike—the necessity of repenting from sin and turning to God, and of having faith in our Lord Jesus."

Acts 26:20 (NLT):
"I preached first to those in Damascus, then in Jerusalem and throughout all Judea, and also to the Gentiles, that all must repent of their sins and turn to Godand prove they have changed by the good things they do."

Titus 2:14 (NLT):
"He gave his life to free us from every kind of sin, to cleanse us, and to make us his very own people, totally committed to doing good deeds."

***God desires a spiritual circumcision (metanoia/change of heart) from both Jews and Gentiles.***

Romans 2:29 (NLT):
"No, a true Jew is one whose heart is right with God. And true circumcision is not merely obeying the letter of the law; rather, it is a change of heart produced by the Spirit. And a person with a changed heart seeks praise from God, not from people."

Isaiah 55:6-7 (NLT):
"Seek the Lord while you can find him.
    Call on him now while he is near.
7 Let the wicked change their ways
    and banish the very thought of doing wrong.
Let them turn to the Lord that he may have mercy on them.
    Yes, turn to our God, for he will forgive generously."

Matthew 3:8 (NLT):
"Prove by the way you live that you have repented of your sins and turned to God."

Please also refer to my post- "What Must You Do To Be Saved?".