Its the result of Christs obedience for the many Rom 5:19
19 For as by one man's disobedience many were made sinners, so
by the obedience of one shall many be made righteous.
Interestingly the word made here καθίστημι means:
- to set down as, constitute, to declare, show to be
To be declared righteous also means to be justified
Isa 53:11
He shall see of the travail of his soul,
and shall be satisfied:
by his knowledge shall my righteous servant justify many; for he shall bear their iniquities.
Justify here means to declare righteous
rom the trouble of his life[
f] he will see;[
g]
he will be satisfied.
In his knowledge,
the righteous
one, my servant,
shall declare many righteous,[h]
and he is the one who will bear their iniquities. LEB
So it also means to be declared Just or Justified.