"Modern day" Judaizers who place an emphasis on salvation by faith + obeying the 10 commandments (with a heavy emphasis on the 4th commandment).
It is not that we are required to add our good works to our faith as if our faith alone were insufficient for salvation but rather the significance of being a doer of good works is that it is expressing our faith and it is by that faith that we are saved. In Hebrews 11, every example of faith is an example of works. In Proverbs 3:5-7, we have a choice between whether we are going lean on our own understanding of right and wrong by doing what is right in our own eyes or whether we are going to trust in God with all of our heart to correctly divide between right and wrong through obeying God’s instructions in all of our ways and He will make our way straight. So again it is not that we need to add our good works to our trust alone were insufficient, but that being a doer if good works is the way to trust God with all of our heart.