Faith is belief in action.
Biblical faith is belief in the promises of God and working through one's life with those promises as our conerstone and foundation.
God had promised Abraham descendants as numerous as the stars.
Genesis 15:5 And he brought him forth abroad, and said, Look now toward heaven, and tell the stars, if thou be able to number them: and he said unto him, So shall thy seed be.
God also promised him that his descendants would come through Isaac.
Genesis 21:12 And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah hath said unto thee, hearken unto her voice; for in Isaac shall thy seed be called.
Abraham believed God’s promises.
When God told him to offer Isaac as a sacrifice he obeyed.
He reasoned that because God’s promise concerning his descendants was through Isaac, that if Isaac were slain, God would raise him from the dead.
This is explained by the writer to the Hebrews:
Hebrews 11:17 By faith Abraham, when he was tried, offered up Isaac: and he that had received the promises offered up his only begotten son, 18 Of whom it was said, That in Isaac shall thy seed be called: 19 Accounting (reasoning/reckoning) that God was able to raise him up, even from the dead; from whence also he received him in a figure.
James explains that faith (belief) without works is dead, and that Abraham’s offering of Isaac was a work of faith.
James 2:20 But wilt thou know, O vain man, that faith without works is dead? 21 Was not Abraham our father justified by works, when he had offered Isaac his son upon the altar? 22 Seest thou how faith wrought with his works, and by works was faith made perfect? 23 And the scripture was fulfilled which saith, Abraham believed God, and it was imputed unto him for righteousness: and he was called the Friend of God.
Faith is not blind, it must be based on reason.
Faith, belief in God's promises, is essential if we would please God.
Hebrews 11:6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
The source of faith is the scriptures because they explain the promises of God.
Romans 10:17 So then faith cometh by hearing, and hearing by the word of God.
When we understand and believe the Bible, we acquire faith in God.
When we obey God, we work the works of faith.
James 2:17 Even so faith, if it hath not works, is dead, being alone. 18 Yea, a man may say, Thou hast faith, and I have works: shew me thy faith without thy works, and I will shew thee my faith by my works.
Abraham is a good example of faith because he was prepared to sacrifice his son because he believed God.
Faith is what will save us, because faith is reckoned by God for the righteousness that we cannot achieve.
Romans 4:16 Therefore it (salvation) is of faith, that it might be by grace; to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all, 17 (As it is written, I have made thee a father of many nations,) before him whom he believed, even God, who quickeneth the dead, and calleth those things which be not as though they were. 18 Who against hope believed in hope, that he might become the father of many nations, according to that which was spoken, So shall thy seed be. 19 And being not weak in faith, he considered not his own body now dead, when he was about an hundred years old, neither yet the deadness of Sara’s womb: 20 He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God; 21 And being fully persuaded that, what he had promised, he was able also to perform. 22 And therefore it was imputed to him for righteousness. 23 Now it was not written for his sake alone, that it was imputed to him; 24 But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead; 25 Who was delivered for our offences, and was raised again for our justification.
Faith for us consists of believing and obeying the Gospel preached by Jesus Christ and his apostles.
Jesus Christ is the descendant promised to Abraham in whom all nations of the earth will be blessed.
Genesis 12:3 And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed.
Galatians 3:16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
I hope you find this helpful.