The emphasis on soteriology in Revelation has mainly to do with perseverance. Christ is introduced (ch. 1) as the one who died and was raised again. Christ is also the Lamb slain (ch. 5) who calls the thirsty to drink of the water of life (ch. 22).
Those who claim Christ as Savior must evidence this salvation by their loyalty to him. The letters to the seven churches in chs. 2-3 are predicated upon knowledge of the allegiance the church owes to Christ. These letters promise curses to those who are not faithful to Christ and promise blessing even to those who have turned aside from him provided they repent and follow Christ once again, even to the point of death. The martyrs who are under the throne (ch. 6) are those who were faithful to death. In the rest of the book, it is assumed that believers will remain loyal to the Lord until death and these will be received into the new heavens and new earth to enjoy God’s presence for eternity as reward for their faithfulness.
Those who are faithful to Christ are “conquerors” and these conquerors maintain their witness and through it have overcome the world by the “blood of the lamb” and by “the word of their testimony” (5:5-6; 12:11). So this is not a works-salvation but a faithfulness worked out by God through Christ’s saving power.