Some, I think do it, because
they don’t want to seem to be too "Pentecostal".
Most probably because the
church they grew up in, or the Bible school they went
to, didn’t say Holy Ghost very often.
It’s only strange when they
correct someone for, or stop someone from, saying Holy
Ghost, since it is in the scriptures.
Consider the word Spirit, by
itself, used for the LORD's Spirit, i.e. not proceeded
by the word “Holy”.
It is used in both
testaments, over 200 times, e.g. Spirit of the LORD,
etc., and even a few times not capitalized.
Holy Ghost is exclusively
used in the New Testament 89 times.
Holy Spirit is only used 7
times, 3 times in the old testament, and 4 in the new.
There are even four
scriptures where both Spirit and Holy Ghost are used
at the same time:
Luke 4:1 And Jesus being full
of the Holy Ghost returned
from Jordan, and was led by the Spirit into the wilderness,
John 1:33 And I knew him not:
but he that sent me to baptize with water, the same
said unto me, Upon whom thou shalt see the Spirit descending,
and remaining on him, the same is he which baptizeth
with the Holy Ghost.
John 7:39 (But this spake he
of the Spirit, which they that believe on him
should receive: for the Holy Ghost was not
yet given; because that Jesus was not yet glorified.)
I Corinthians 12:3 Wherefore
I give you to understand, that no man speaking by the Spirit of God
calleth Jesus accursed: and that no man can say that
Jesus is the Lord, but by the Holy Ghost.
When I’ve had the opportunity
to teach about him, the question comes up about the
difference between the two terms.
I’ve taught that it looks
like the two uses seem to be for different purposes.
It looks, at least to me,
that Spirit more often describes him, whereas Holy
Ghost appears to identify him.