# Your conduct among the Gentiles should be honorable

"When you are with the Gentiles, you should always act in an honorable way"

# honorable

morally good

# they may be eyewitnesses of your good deeds

"they may be eyewitnesses of the good things that you do" 

# on the day when he appears

"on the day when he comes." This refers to the day when God will judge all people. Alternate translation: "when he comes to judge everyone"