Salvation has ALWAYS been by faith.
It's a matter of how that faith is expressed and how God deals with mankind under the different covenants, otherwise known as dispensations.
Works are always the outcome of faith. Under the old covenant, people were judged by those works as to whether their faith was real saving faith or not because Jesus hadn't come.
Under the new covenant, people are judged by their faith in the revealed Redeemer, their response to Jesus.
Galatians 2:15-21 15We ourselves are Jews by birth and not Gentile sinners; 16yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified.
17But if, in our endeavor to be justified in Christ, we too were found to be sinners, is Christ then a servant of sin? Certainly not! 18For if I rebuild what I tore down, I prove myself to be a transgressor. 19For through the law I died to the law, so that I might live to God. 20I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me.
21I do not nullify the grace of God, for if righteousness were through the law, then Christ died for no purpose.
Galatians 3:1-29 1 O foolish Galatians! Who has bewitched you? It was before your eyes that Jesus Christ was publicly portrayed as crucified. 2Let me ask you only this: Did you receive the Spirit by works of the law or by hearing with faith? 3Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh? 4 Did you suffer so many things in vainif indeed it was in vain? 5Does he who supplies the Spirit to you and works miracles among you do so by works of the law, or by hearing with faith 6just as Abraham "believed God, and it was counted to him as righteousness"?
7Know then that it is those of faith who are the sons of Abraham. 8And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, "In you shall all the nations be blessed." 9So then, those who are of faith are blessed along with Abraham, the man of faith.
10For all who rely on works of the law are under a curse; for it is written, "Cursed be everyone who does not abide by all things written in the Book of the Law, and do them." 11Now it is evident that no one is justified before God by the law, for "The righteous shall live by faith." 12But the law is not of faith, rather "The one who does them shall live by them."
13Christ redeemed us from the curse of the law by becoming a curse for usfor it is written, "Cursed is everyone who is hanged on a tree" 14so that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promised Spirit through faith.
15 To give a human example, brothers: even with a man-made covenant, no one annuls it or adds to it once it has been ratified. 16Now the promises were made to Abraham and to his offspring. It does not say, "And to offsprings," referring to many, but referring to one, "And to your offspring," who is Christ. 17This is what I mean: the law, which came 430 years afterward, does not annul a covenant previously ratified by God, so as to make the promise void. 18For if the inheritance comes by the law, it no longer comes by promise; but God gave it to Abraham by a promise.
19Why then the law? It was added because of transgressions, until the offspring should come to whom the promise had been made, and it was put in place through angels by an intermediary. 20Now an intermediary implies more than one, but God is one.
21Is the law then contrary to the promises of God? Certainly not! For if a law had been given that could give life, then righteousness would indeed be by the law. 22But the Scripture imprisoned everything under sin, so that the promise by faith in Jesus Christ might be given to those who believe.
23Now before faith came, we were held captive under the law, imprisoned until the coming faith would be revealed. 24So then, the law was our guardian until Christ came, in order that we might be justified by faith. 25But now that faith has come, we are no longer under a guardian, 26for in Christ Jesus you are all sons of God, through faith.27For as many of you as were baptized into Christ have put on Christ. 28 There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus. 29And if you are Christs, then you are Abrahams offspring, heirs according to promise.
How sad that so many attempt to put themselves under the law.
Faith without works is DEAD.