The events in this conditional statement have happened. The false teachers had at one time escaped, but they became entangled and were overcome. Alternate translation: "Since they have escaped ... and are again entangled in them and overcome"
The word "corruption" refers to sinful behavior that makes one morally impure. The "world" refers to human society. Alternate translation: "the corrupting 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](../01/02.md). Alternate translation: "by knowing the Lord and Savior Jesus Christ" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])