The words “HOLY SPIRIT” in the Bible are primarily used in two very different ways: One way is to refer to God Himself and the other is referring to God’s nature that He gives to people. God is holy and is spirit and therefore “the Holy Spirit” with a capital “H” and a capital “S” is one of the many “names” or designations for God. God gives His holy spirit nature to people as a gift and when HOLY SPIRIT is used that way it should be translated as the “holy spirit” with a lowercase “h” and a lowercase “s.” The Bible says there is one God, and one Lord, who is the man Jesus Christ; and one gift of the holy spirit. Most Christians are aware that the original manuscripts of the Bible were written in Hebrew, Aramaic, and Greek. However, it's not well known that Hebrew and Aramaic do not have upper-case and lower-case letters, but rather they just have one form for their letters.
Greek does have upper and lower-case letters, but the early Greek manuscripts were all written with only upper-case letters. Therefore, the early manuscripts had no such thing as the “Holy Spirit” or the “holy spirit” because what was always written was the "HOLY SPIRIT." The capital or lower-case letters are always a translator’s interpretation whenever we read “Holy Spirit” or “holy spirit” or “Spirit” or “spirit” in the English Bible. The difference is usually due to the theology of the translator. The bottom line is we cannot know from the Hebrew or Greek texts whether the Author meant the “Holy Spirit” or the “holy spirit” because we must decide based on the context and scope of Scripture whether the reference being made is to God or God’s gift.