Is It Okay to Join an Organization That Supports Abortion?

Questions about whether it’s morally okay to join and pay dues to an organization that supports abortion in order to influence the organization, whether the verse that says people from “every nation” will be in Heaven includes the Canaanites, and how to respond to someone who says sexuality doesn’t need to be understood, just accepted. 

• Is it morally okay to join and pay dues to an advocacy organization that also supports abortion in order to influence the people and the organization?
• Does the statement in Revelation 7:9 that says people “from every nation, tribe, people, and language” will be in Heaven include Canaanites, Hittites, Jebusites, etc.?
• How would you respond to the claim “Sexuality isn’t something we need to understand; sexuality is something we need to accept.”