The word "whosoever" means all, everyone, anyone. (Funk and Wagnalls Dictionary)
If you try to say that only the "elect" are the whosoever's then the word loses its meaning. It is not possible to define the word "whosoever" to any particular person or group, it just doesn't make sense to try and do so.
The word "whosoever" appears in the Bible over 180 times. Jesus used the word "whosoever" over 80 times. Such as in John 3:16, where he said, "That WHOSOEVER believes in him should not perish, but have everlasting life."
The Bible plainly teaches that salvation is for "whosoever" that believes in Jesus. To try and change that is to deceive yourself into believing a lie.