In final, all knees will bow to Jesus Christ as God The Saviour (Philippians 2). That's going to happen during Christ's future "thousand years" reign with His elect priests and kings. For He must reign until all His enemies are put under His feet. Yet some will still reject Him and perish forever.
That is another one of the main differences between Christianity and other religions like Islam. Even after our Lord Jesus returns back to this earth, and rules over all for a thousand years, with His glory revealed here on earth, the rebellious will still refuse to accept His Salvation. That means they themselves choose to perish of their own choice.
But other religions preach forced conversion, not giving a choice, which is false salvation. Salvation must be by individuals choosing it, not forced upon them.