Two sorts of Grace to compare: Noahic Grace vs JC Grace
Grace unto you, and peace,
from God our Father and the Lord Jesus Christ.
If the sort of "grace" Noah found in the eyes of the LORD was neither merciful nor impartial: only saved eight souls to keep seed alive, and later ended bad for all, even for Noah: got inducted in the hall of shame: these all died and received not the promise (Hebrews 11) ... And if we're later told "grace" and truth came by Jesus Christ: John 1:17 ...
Then perhaps there are two sorts of grace to sort in two testaments; The new testatment being called the "better testament" having a "better hope" of all living and none perishing by the JC sort of grace; Eternal life being "through Jesus-->Christ", "in Christ" thereof such Lawed Grace-->Pure Grace.
http://www.godshew.org/TwainShew3.htm#Graces
Save some: is also a biblical principle, even with Apostle Paul in the NT; But the purpose of "save some" seems to be a temporal principle, to scuttle "all perish" (by law: Col 2:20-22) till we all are one get to the point of none perish by grace void of law. For a higher exhortation of Paul seems to be: "there is no respect of persons with God"; And "ye/we are not under the law, but under grace", which applies to both Jews and Gentiles.
Law wasn't merciful, and was parital: save some
His Grace is merciful and not partial: save all
So the grace Noah found in the eyes of the LORD was not sufficient to save all, nor of God, but found in the eyes of the LORD(LAW). And in the flood story we find both God and the LORD, with Noah doing both: all God commanded and all the LORD commanded; Yet they were contrary commandments from contrary Commanders, and doing both got Noah inducted into the hall of shame: these all died and received not the promise.
In comparison and contrast we find Paul being told: My grace is sufficient for thee. Sufficient speaks of save all, not some; Of bless all and curse none; Of pure grace void of law. So in all Pauline conclusions of Pauline epistles, we find the sort of grace that is "with you all" (against none) clarified as the grace of our Lord Jesus Christ. So ends the Bible:
The GRACE of our Lord Jesus Christ with you all. Amen.
