‘There were sealed an hundred and forty and four thousand of all the tribes of the children of Israel.’ Is that a literal figure? No; like all numbers in this book, it is a symbolic figure.
There is a perfect number known to God – ‘an hundred and forty four thousand’. It is a special number, a complete number. It represents the elect of God in all ages. This perfect number is a symbol telling us that the real number is known to God. It means that everyone who is sealed in the history of the gospel age (and those who believed in Old Testament times) is intended to be sealed by God, and will be kept secure until the last day. In the last day, the roll of the elect will be complete, a perfect number, none missing. Not one will have been lost. The symbolism is about the security of the believer. That is why it is described both ways.