Hi Tameria,
I think the goal of Bible believing Christians encountering Jehovah's Witnesses is to BLESS them with both:
a. doubt in their organization and
b. the biblical gospel of salvation
Those without religious faith might seek to simply bless them with:
a. doubt in their organization
I think the best way to accomplish a. is to question your friends (i.e., ask them to substantiate) one or two of the unique beliefs and/or policies of their organization. One of my favorite topics would be their blood policies. The blood issue is a great one to start with since everyone knows about their refusal to accept whole blood and so you would not be giving your past association away. Cofty produced a great study on blood and there is much info on line that you can research.
http://www.ajwrb.org/watchtower-approved-blood-transfusions
Neither Acts 15, nor Leviticus 11 or 17 informs Christians
a. which components of blood are acceptable and which ones are not.
b. why plasma is unacceptable when all of its elements and fractions are on the WTS acceptable list.
c. why white blood cells are banned when 97 percent of the white cells are not found in the blood stream but in organ tissues that are permitted by the WTS to transplant.
d. that it is sinful to store whole blood for any reason except in small amounts in tubes for lab technicians to test
e. that it is morally right to use the fractions derived from the donated and stored blood of others and that without contributing anything to blood banks themselves?
f. that it is permitted to restore blood to the body after it has been cleaned..only if there is no interruption in it's flow back to the body.