It’s a truism, arising primarily from the Pauline letters, in Protestant (biblical) theology that ‘justification’ happens in the past, and ‘sanctification’ happens in the present. That is, believers have been justified and they are being sanctified.
In my work in the connection between resurrection and justification, I was rereading Sanders’ Paul and Palestinian Judaism, and he, almost as a throw away observation, notes this:
… his view [is] that the Christians have been sanctified (hegiasmenois, 1 Cor 1.2) [and] his other principle word for them, besides ‘believers’, is ‘saints’ (hagioi): thus Rom 1.7; 8.27; 1 Cor 1.2 and very frequently. Although Christians are also said to have been ‘justified’ (1 Cor 6.9-11; Rom 8.30), he does not call them ‘the righteous’ , dikaioi …. (PPJ, 452)
Past sanctification is such a sure thing that Paul frequently calls believers ‘saints’. But why would he not call believers ‘the righteous’? (The church’s moral holiness wasn’t the source of the term ‘saints’, as Paul’s letters are constantly telling them to act better.)