Why faith?

2 Timothy 3:16-17 Authorized (King James) Version (AKJV)    "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: that the man of God may be perfect, throughly furnished unto all good works."

Concerning "faith", many questions with answers are found in scripture.  First off "All scripture is given by inspiration of God,".  I then will either believe that or will protest and in protesting will make my own versions to suit what I think is or isn't God's Word.  

"Now faith is the substance of things hoped for, the evidence of things not seen."  Hebrews 11:1.  Although not seen we as God's children can know what is not only seen but what is not seen by faith.  

"But as it is written, Eye hath not seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love him. But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God. For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God. Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God. Which things also we speak, not in the words which man’s wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual. But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned. But he that is spiritual judgeth all things, yet he himself is judged of no man. For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ." 1 Corinthians 2:9-16

Faith as used in scripture:  "your faith", 'mutual faith", "faith to faith", "faith of Jesus Christ", "through faith", "law of faith", "justified by faith", "his faith", "yah faith", "the faith", "that faith", "righteousness of faith", "in faith", 

"by faith", "word of faith", "then faith", "measure of faith", "proportion of faith", "not of faith", "obedience of faith".  This is just a sampling from Romans how the Holy Spirit by Paul explained faith.  We then must "Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth."  2 Timothy 2:15.  Also being advised by Isaiah writing: "For precept must be upon precept, precept upon precept; line upon line, line upon line; here a little, and there a little:

Isaiah 28:10

 "Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;) and hath raised us up together, and made us sit together in heavenly places in Christ Jesus: that in the ages to come he might shew the exceeding riches of his grace in his kindness toward us through Christ Jesus. For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: not of works, lest any man should boast. For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them."

Ephesians 2:5-10

"For by grace are ye saved through faith;"  we are saved by believing the truth, the truth of the gospel that saves us today; "Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; by which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; and that he was buried, and that he rose again the third day according to the scriptures:" 1 Corinthians 15:1-4.  

"And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth."  John 1:14.  "God is a Spirit: and they that worship him must worship him in spirit and in truth."  John 4:24.  

When we believe the gospel we are immediately:  "For by one Spirit are we all baptized into one body [spirituially, not water], whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit."  1 Corinthians 12:13. We are eternally secure:  "In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will: that we should be to the praise of his glory, who first trusted in Christ. in whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise, which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory."  Ephesians 1:11-14.  

In conclusion;  I am made a new creation in Christ Jesus by believing the gospel.  All else is on Him, the doing of, then maintaining and the end.  It is His faithfulness to His Word and us.  He is the one who does all that is required to bring, make, keep and present us, the believer, to Himself.  I am to believe and then rest in Him.  That resting gives me liberty to learn who I am in Him, what He has purposed for me and to do the work He has given me to do.  I need to know why I am accepted by Him by study to see how He has provided to me all and abundantly over all that I can ever know of and use in Him.  I don't work for salvation but after I am given life in Him I work the work that He has provided to bring Him glory, lifting His name which is above every name given which by we are saved.  As I grow in that grace given I will not be ashamed of Him or His Words but will learn how to  "rightly divide" the Word of truth; being "times past", 'but now" and "ages to come".  This is found in Ephesians 2:1-10.