The Lord God Almighty has decreed that when the time comes for Jesus to be fully revealed, everyone who should be sealed must be sealed, whether they are in the millennial kingdom or in the eternal kingdom. Many who believe that they cannot be sealed are in fact scheduled to be in the millennial kingdom of God.
Ask the indwelling Holy Spirit Of God whether or not you can be sealed. If he says "yes" ask him to tell you what you should do in order to become sealed. Listen in your heart to his response, and do exactly what he tells you to do. Do it now.
The Lord God Almighty El Shaddai