2 Timothy3:
16 All scripture
is given by inspiration of God, and
is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
17 That the man of God may be perfect, throughly furnished unto all good works.
They used the Old Testament.
Romas3:10 As it is written,
There is none righteous, no, not one:
11 There is none that understandeth, there is none that seeketh after God.
Romans3:
21 But now the righteousness of God without the law is manifested, being witnessed by the law and the prophets
22 Even the
righteousness of God which is by faith of Jesus Christ unto all and upon all them that
believe: for there is no difference:
23 For all have sinned, and come short of the glory of God;
24 Being justified freely by his grace through the redemption that is in Christ Jesus:
25 Whom God hath set forth
to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;
26 To declare,
I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus.
They were the exception not the rule. Just like the thief on the cross.