I saw this above video recently and had to share it, I think it catches the heart of exactly why and how we can reach Jehovahs Witnesses, and why it is so important.
Too often Christians see Jehovahs Witnesses as some kind of enemy to be avoided, this is so far from the case, Ephesians 6:12 says our struggle is not against flesh and blood. We should remember this when meeting people who are following a false system, they are not the enemy no matter how insistent they are, and we should love them and speak to them, and live out this great verse.
1 Peter 3:15
But in your hearts revere Christ as Lord. Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect,