Yes, Romans four and the example of Abraham does apply to us today. Notice verse 3, “For what does the Scripture say? “Abraham believed God, and it was counted to him as righteousness.” The context and purpose of Romans 4 was to show that righteousness does not come by the strict observance of the law of Moses. One cannot merit salvation on the basis of works alone, we are saved by grace through faith (Ephesians 2:8). Neither can we obtain salvation on the basis of faith alone, “So also faith by itself, if it does not have works, is dead.” (James 2:17). We are not justified by “faith alone” (James 2:24).
The Bible is its own best interpreter. When it tells us what it means, then that is the way it is. James 2:17-26 is an inspired commentary on Romans 4, “Do you want to be shown, you foolish person, that faith apart from works is useless? 21 Was not Abraham our father justified by works when he offered up his son Isaac on the altar? 22 You see that faith was active along with his works, and faith was completed by his works; 23 and the Scripture was fulfilled that says, “Abraham believed God, and it was counted to him as righteousness… You see that a person is justified by works and not by faith alone.” When was Abraham justified by faith? Verse 21 says “When he offered up his son Isaac.” Abraham believed God. He had faith God would accomplish what he said. But it was not until Abraham OBEYED the command of God that his faith was counted for righteousness. “ And in the same way was not also Rahab the prostitute justified by works when she received the messengers and sent them out by another way?” (v. 25)? Here is another example of faith WORKING, OBEYING, and it is at that point that faith is counted righteous in the sight of God.
The same can and will be done for us WHEN we OBEY the commands of God. We are saved by faith WHEN that faith OBEYS. “But thanks be to God, … have become obedient from the heart to the standard of teaching to which you were committed, 18 and, having been set free from sin, have become slaves of righteousness.” (Romans 6:17-18). The doctrine they obeyed was the doctrine of water baptism mentioned in verses 3-6 of the same chapter. When we BELIEVE and OBEY by REPENTING, CONFESSING and being BAPTIZED, we too will be counted righteous before God.