The word "defilements" refers to sinful behavior that makes one morally impure. The "world" refers to human society. Alternate translation: "the defiling practices of sinful human society" (See: [[rc://en/ta/man/translate/figs-metonymy]])
You can translate "knowledge" using a verbal phrase. See how you translated similar phrases in [2 Peter 1:2](../01/01.md). Alternate translation: "by knowing the Lord and Savior Jesus Christ" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])