It doesn't matter what anyone adds to or takes away from the word, but that they will be held accountable for doing so, Rev 22:18, 19. It's all about first having faith and belief in Christ Jesus who is our free gift of grace from God as salvation is through Christ Jesus and His finished works on the cross. We do not deserve it nor are we worthy of it and our own righteousness is as a filthy rag to God as we are made righteous by His righteousness.
Faith is necessary to salvation unconditionally. Good works are necessary only conditionally, that is if there is time and opportunity, but yet our best efforts can never be good enough to earn salvation. It is God that declares us righteous for Christ's sake as He sanctifies us and sets us apart for we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.
Below verses are about faith and belief alone, not of works. I could give many many more, but these are sufficient enough.
Genesis 15:6 And he believed in the LORD; and he counted it to him for righteousness.
Habakkuk 2:2 And the LORD answered me, and said, Write the vision, and make it plain upon tables, that he may run that readeth it. 3 For the vision is yet for an appointed time, but at the end it shall speak, and not lie: though it tarry, wait for it; because it will surely come, it will not tarry. 4 Behold, his soul which is lifted up is not upright in him: but the just shall live by his faith.
Galatians 2:16; 3:24; Romans 1:17; 3:28; 4:5; Romans 5:9; 11:6; Philippians 3:9; James 2:23, 24; Ephesians 2:8, 9; John 1:12; 3:16; Acts 16:31