Yes. Believers are in the world. From the past, present and future.
God testifies of His Existence by creation.
Jesus paid the sin debt of believers only. If He paid the sin debt of the WHOLE WORLD then preaching is not necessary. Scripture is not necessary. There is nothing to convict anyone of. It has all been atoned for.
Can't reason with someone who needs to be saved before they can understand. You can only reason with someone who is already saved and understands.
Whosoever means everyone the Father draws to Christ, past, present and future.