Decoding Isaiah 1:21

faithful: {1} support
(H539)
Proverbs 25:13  As the cold of snow in the time of harvest, so is a faithful messenger to them that send him: for he refresheth the soul of his masters. 

{2} serving God's Commandments
Psalms 101:6  Mine eyes shall be upon the faithful of the land, that they may dwell with me: he that walketh in a perfect way, he shall serve me. 

{3} establishing a permanent assurance
(H539)
Deuteronomy 7:9  Know therefore that the LORD thy God, he is God, the faithful God, which keepeth covenant and mercy with them that love him and keep his commandments to a thousand generations; 
Nehemiah 9:8  And foundest his heart faithful before thee, and madest a covenant with him to give the land of the Canaanites, the Hittites, the Amorites, and the Perizzites, and the Jebusites, and the Girgashites, to give it, I say, to his seed, and hast performed thy words; for thou art righteous: 

{4} loyalty
Numbers 12:7  My servant Moses is not so, who is faithful in all mine house. 
1st Samuel 2:35  And I will raise me up a faithful priest, that shall do according to that which is in mine heart and in my mind: and I will build him a sure house; and he shall walk before mine anointed for ever. 
Proverbs 20:6  Most men will proclaim every one his own goodness: but a faithful man who can find? 

{5} certainty
Proverbs 27:6  Faithful are the wounds of a friend; but the kisses of an enemy are deceitful.

{6} recording
Isaiah 8:2  And I took unto me faithful witnesses to record, Uriah the priest, and Zechariah the son of Jeberechiah. 

{7} Godly trait of being trustworthy
1st Corinthians 1:9  God is faithful, by whom ye were called unto the fellowship of his Son Jesus Christ our Lord. 
(H539)
(Exodus 4:1  And Moses answered and said, But, behold, they will not believeH539 me, nor hearken unto my voice: for they will say, The LORD hath not appeared unto thee.)
(G4103)

{8} Living in a perfect way
Psalms 101:6  Mine eyes shall be upon the faithful of the land, that they may dwell with me: he that walketh in a perfect way, he shall serve me. 
Nehemiah 9:8  And foundest his heart faithful before thee, and madest a covenant with him to give the land of the Canaanites, the Hittites, the Amorites, and the Perizzites, and the Jebusites, and the Girgashites, to give it, I say, to his seed, and hast performed thy words; for thou art righteous: 
1st Samuel 22:14  Then Ahimelech answered the king, and said, And who is so faithful among all thy servants as David, which is the king's son in law, and goeth at thy bidding, and is honourable in thine house? 

{9} the fruit thereof is abundantly obvious
Nehemiah 13:13  And I made treasurers over the treasuries, Shelemiah the priest, and Zadok the scribe, and of the Levites, Pedaiah: and next to them was Hanan the son of Zaccur, the son of Mattaniah: for they were counted faithful, and their office was to distribute unto their brethren. 

{10} starts within the heart
Nehmiah 9:8  And foundest his heart faithful before thee, and madest a covenant with him to give the land of the Canaanites, the Hittites, the Amorites, and the Perizzites, and the Jebusites, and the Girgashites, to give it, I say, to his seed, and hast performed thy words; for thou art righteous: