The word "secret" describes the things that people do secretly. Things that are shameful should cause people who do them to feel ashamed. Alternate translation: "the things that people do secretly because they cause shame" (See: [[rc://en/ta/man/jit/figs-hendiadys]])
The word "walk" is a metaphor for the way a person lives his life. Alternate translation: "live by deceiving people" (See: [[rc://en/ta/man/jit/figs-metaphor]])
The phrase "word of God" here is a metonym for the message from God. The words "we do not mishandle" use two negative thoughts to express a positive thought. Alternate translation: "we handle God's message correctly" or "we use the word of God properly" (See: [[rc://en/ta/man/jit/figs-doublenegatives]] and [[rc://en/ta/man/jit/figs-metonymy]])
This refers to God's presence. God's understanding and approval of Paul's truthfulness is referred to as God being able to see them. Alternate translation: "before God" or "with God as witness" (See: [[rc://en/ta/man/jit/figs-metaphor]])