Peace with enemies

Proverbs 16:7 (KJV) When a man's ways please the LORD, he maketh even his enemies to be at peace with him.

If you are saved and, in spite of your best efforts (Romans 12:18), still have enemies, you may wonder about this verse. 

But you needn't, because Proverbs is first and foremost a book of wisdom for Israel. 

This verse references the kingdom for Israel. When their ways please the LORD (ie when they go into the kingdom) then will their enemies be at peace with them. This was prophesied... 

Isaiah 60:14 (KJV)  The sons also of them that afflicted thee shall come bending unto thee; and all they that despised thee shall bow themselves down at the soles of thy feet; and they shall call thee, The city of the LORD, The Zion of the Holy One of Israel.

Zechariah 8:22-23 (KJV) Yea, many people and strong nations shall come to seek the LORD of hosts in Jerusalem, and to pray before the LORD.  Thus saith the LORD of hosts; In those days it shall come to pass, that ten men shall take hold out of all languages of the nations, even shall take hold of the skirt of him that is a Jew, saying, We will go with you: for we have heard that God is with you.

... and was foreshadowed on several occasions in Israel's history, this being one of them:

Genesis 26:28 (KJV) And they (Philistines) said, We saw certainly that the LORD was with thee (Isaac): and we said, Let there be now an oath betwixt us, even betwixt us and thee, and let us make a covenant with thee;

Final point on the non-application of this verse in the dispensation of grace. Paul's ways pleased the Lord (2 Timothy 4:7-8), but it is fair to say he had his share of enemies who were not at peace with him (Acts 14:19; 20:3; 21:31; 23:12-15, amongst others).