Why do you think that?.
The OT Jews had the Law for their salvation.
Becoming a Christian after death is ludicrous...and too late.
Therefore by the deeds of the law no flesh will be justified in His sight, for by the law is the knowledge of sin. (Rom. 3:20 NKJ)
No one was saved by the law, all are saved by Jesus Christ:
19 Now we know that whatever the law says, it says to those who are under the law, that every mouth may be stopped, and all the world may become guilty before God.
20 Therefore by the deeds of the law no flesh will be justified in His sight, for by the law is the knowledge of sin.
21 But now the righteousness of God apart from the law is revealed, being witnessed by the Law and the Prophets,
22 even the righteousness of God, through faith in Jesus Christ, to all and on all who believe. For there is no difference;
23 for all have sinned and fall short of the glory of God,
24 being justified freely by His grace through the redemption that is in Christ Jesus,
25 whom God set forth as a propitiation by His blood, through faith, to demonstrate His righteousness, because in His forbearance God had passed over the sins that were previously committed,
26 to demonstrate at the present time His righteousness, that He might be just and the justifier of the one who has faith in Jesus.
27 Where is boasting then? It is excluded. By what law? Of works? No, but by the law of faith.
28 Therefore we conclude that a man is justified by faith apart from the deeds of the law.
29 Or is He the God of the Jews only? Is He not also the God of the Gentiles? Yes, of the Gentiles also,
30 since there is one God who will justify the circumcised by faith and the uncircumcised through faith.
31 Do we then make void the law through faith? Certainly not! On the contrary, we establish the law.
NKJ Romans 4:1 What then shall we say that Abraham our father has found according to the flesh?
2 For if Abraham was justified by works, he has something to boast about, but not before God.
3 For what does the Scripture say? "Abraham believed God, and it was accounted to him for righteousness."
4 Now to him who works, the wages are not counted as grace but as debt.
5 But to him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness,
6 just as David also describes the blessedness of the man to whom God imputes righteousness apart from works:
7 "Blessed are those whose lawless deeds are forgiven, And whose sins are covered;
8 Blessed is the man to whom the LORD shall not impute sin."
(Rom. 3:19-4:8 NKJ)