Do the Witnesses believe that their religion is the only right one?
Anyone who is serious about his religion should think that it is the right one. Otherwise, why would he or she be involved in it? Christians are admonished: "Make sure of all things; hold fast to what is fine." ( 1 Thessalonians 5:21 ) A person should make sure that his beliefs can be supported by the Scriptures, for there is only one true faith. Ephesians 4:5 confirms this, mentioning "one Lord, one faith, one baptism." Jesus did not agree with the modern, relaxed view that there are many roads, many religions, all leading to salvation. Instead, he said: "Narrow is the gate and cramped the road leading off into life, and few are the ones finding it." Jehovah's Witnesses believe that they have found it. Otherwise, they would look for another religion.— Matthew 7:14 .
Do they believe that they are the only ones who will be saved?
No. Millions that have lived in centuries past and who were not Jehovah's Witnesses will come back in a resurrection and have an opportunity for life. Many now living may yet take a stand for truth and righteousness before the "great tribulation," and they will gain salvation. Moreover, Jesus said that we should not be judging one another. We look at the outward appearance; God looks at the heart. He sees accurately and judges mercifully. He has committed judgment into Jesus' hands, not ours.— Matthew 7:1-5 ; 24:21 ; 25:31 .
So, it's no longer necessary to be a JW to be saved?