Answer:

"My son, if sinners entice you, do not consent" (Proverbs 1:10).

The dilemma occurs solely because you consider this person to be a friend of yours. If it wasn't for that friendship, you would know what you needed to do.

A true friend improves his friends even while at times disagreeing. "As iron sharpens iron, so a man sharpens the countenance of his friend" (Proverbs 27:17). So if you want to be a friend to this man, you should try to persuade him out of crimes. What he plans to do are criminal acts. They are so sinful acts since it involves lying and stealing. If he listens to you, great! If he doesn't tell him that you can't continue a friendship with a liar and a cheat, and then follow through. "When I say to the wicked, 'You shall surely die,' and you give him no warning, nor speak to warn the wicked from his wicked way, to save his life, that same wicked man shall die in his iniquity; but his blood I will require at your hand. Yet, if you warn the wicked, and he does not turn from his wickedness, nor from his wicked way, he shall die in his iniquity; but you have delivered your soul" (Ezekiel 3:18-19).

If he goes through with it and you do nothing, then you are implicitly giving your approval to what he has done. "And have no fellowship with the unfruitful works of darkness, but rather expose them" (Ephesians 5:11). You will need to write a letter to the insurance company giving the details that you know and then let them handle it.

If he figures out how the insurance company found out, he'll probably hate you for the rest of his life, assuming that he doesn't change. That will be hard, but if people don't demand honesty from society this quagmire we have of immorality will never change.