Gen 6:8 does say Noah found grace in the eyes of the Lord, but this is not this issue at hand.
That Noah had already found grace in the eyes of the Lord, was a just man and a preacher of righteousness and walked with God before he built the ark is a key issue of the heart. (Genesis 6:8-9; 2 Peter 2:5)
The issue at hand is this: would Noah have CONTINUED to find grace in the eyes of the Lord had he disobeyed God and defiantly NOT build the ark as God commanded him. The answer is resounding NO! Noah would have been condemned and died in the flood with the rest of those wicked people. Any claim he would have continued to receive God's grace be saved anyway while disobeying God is completely unfounded and unbiblical.
Well, that was certainly not the case for Noah, so your argument is moot.
The conclusion then is this: grace is not something received UNconditionally where it acts as a blanket to cover all sins of a person UNconditonally regardless of how that person lives.
You put a lot of faith in man's performance and self-preservation and no faith in God's preservation. (Psalm 37:28; Jude 1:1) You also seem to underestimate the grace of God which operates sovereignly in the lives of believers.
1 Corinthians 15:10 - But by the grace of God I am what I am, and His grace toward me did not prove vain; but I labored even more than all of them, yet not I, but the grace of God with me.
2 Corinthians 1:12 - For our proud confidence is this: the testimony of our conscience, that in holiness and godly sincerity, not in fleshly wisdom but in the grace of God, we have conducted ourselves in the world, and especially toward you.
2 Corinthians 12:9 - And He has said to me, "My grace is sufficient for you, for power is perfected in weakness." Most gladly, therefore, I will rather boast about my weaknesses, so that the power of Christ may dwell in me.
Grace is initially received when a person FIRST CONDITIOANLLY obeys and grace is continued to be received as long as a person CONDITIONALLY continues to obey. This is why there is no example to be found in the NT gospel of people receiving grace BEFORE one CONDITIONALLY obeys. So, what you are saying is that we are merely "initially" saved by grace through faith and not by works, but then one maintains their salvation by works. I call that "type 2 works salvation" or salvation by works at the back door. From beginning "have been saved through faith" (Ephesians 2:8) to end "receiving the end of your faith--the salvation of your souls" (1 Peter 1:9) salvation is by grace through faith and is NOT BY WORKS.
1) salvation is received CONDITONALLY upon obedience....no obedience = no grace/no salvation
Choosing to believe the gospel is the act of obedience that saves. (Romans 1:16; 10:16)
2) since grace is received CONDITIONALLY upon obedience, therefore it can be received in vain if a person quits CONDITONALLY obeying = no OSAS
We have access by faith into grace.. (Romans 5:2) Choosing to place our faith in Jesus Christ alone for salvation (choosing to believe the gospel) is the act of obedience that saves. No amount of works can save you. Romans 5:19 - For as by one man’s disobedience many were made sinners, so also by one Man’s obedience many will be made righteous. You need to look to Jesus and not to self for salvation. (1 Corinthians 1:18-21)
Faith only and OSAS are both totally, completely foreign to what the NT teaches.
Don't confuse "faith only" per James 2:24 (empty profession of faith/dead faith that produces no works - James 2:14) with faith that trusts in Jesus Christ alone for salvation and not in works. (Romans 4:2-6; Ephesians 2:8,9; Philippians 3:9) Those who have been saved by grace through faith are saved FOR good works and NOT BY good works. (Ephesians 2:8-10)
OSAS is not foreign to what the NT teaches. (John 6:38-40; 10:27-30; Romans 8:30-39; Romans 11:29; 2 Corinthians 1:22; 2 Corinthians 5:5; Ephesians 1:13-14; Ephesians 4:30; Philippians 1:6; 1 John 2:19; Jude 1:1)
Faith only will NEVER save a person who will not obey.
Faith that never obeys at all is not genuine faith. In James 2:14, we read of one who
SAYS/CLAIMS he has faith but has
no works (to
evidence his claim). That is not genuine faith, but a
bare profession of faith. So, when James asks, "Can
that faith save him?" he is saying nothing against genuine faith, but only against an
empty profession of faith/dead faith. So, James does not teach that we are saved "by" works. His concern is to
show the reality of the faith
professed by the individual (James 2:18) and
demonstrate that the faith
claimed (James 2:14) by the individual is
genuine. Simple!
OSAS will NEVER keep a person UNconditionally saved apart from continued obedience.
Those who truly are saved are new creations in Christ (2 Corinthians 5:17) are preserved in Christ (Jude 1:1) are sealed in Him with the Holy Spirit of promise (Ephesians 1:13) who is the guarantee of our inheritance unto the redemption of the purchased possession.. (Ephesians 1:14) You could never be obedient enough to take away your own sins and earn your salvation. (Romans 3:23; 6:23)
I can see where NOSAS easily leads a person to conditionally trust in works for salvation, which you obviously do. I can see that you need to repent (change your mind) and
place your faith in Jesus Christ alone for salvation (Acts 20:21; Ephesians 2:8,9) You need to choose to believe the gospel by
trusting in the death, burial and resurrection of Christ as the ALL-sufficient means of your salvation. (Romans 1:16; 1 Corinthians 15:1-4)