{Revelation 15:4} Who wouldn't fear you, Jehovah,
and glorify your name?
For you only are fully right.
For all the nations will come and worship before you.
For your righteous acts have been revealed." -- RLIV
The word rendered as "fully right" above is given the general transliteration as HOSIOS (Strong's G3741). Evidently, the contrast here is Jehovah with the many false gods which the nations have worshiped throughout the centuries of this the present evil age. (Galatians 1:4) In the age to come, all the nations, however, will come and worship before Jehovah, and Jehovah will be the only one proven to be fully right. Most translations render HOIOS as "holy", but such a rendering in English does not distinguish HOSIOS from other words often translated as "holy," and thus it can lead to some confusion.
The word HOSIOS is given the following meanings:
Strong's Definition: Of uncertain affinity; properly right (by intrinsic or divine character; thus distinguished from G1342, which refers rather to human statutes and relations; from G2413, which denotes formal consecration; and from G40, which relates to purity from defilement), that is, hallowed (pious, sacred, sure): - holy, mercy, shalt be.
Mounce's Definition: holy, pious, devout; (n.) Holy One; divine decree (Ac 13:34).
Thayer's Definition: undefiled by sin, free from wickedness, religiously observing every moral obligation, pure holy, pious.
Forms of the word HOSIOS may be found in eight verses of the Bible: Acts 2:27; 13:34,35; 1 Timothy 2:8; Titus 1:8; Hebrews 7:26 and Revelation 15:4; 16:5. It is not used in either Acts 3:14 or Romans 1:4.
The word is used of men (other than Jesus), however, in 1 Timothy 2:8 and Titus 1:8, and thus its usage is not limited to that of the Supreme Being. It is used of Jesus in Acts 2:27; 13:35, where it used to quote Psalm 16:10. Peter and Paul used this word to render the Hebrew word often transliterated as CHASIYD (Strong's H2623).
https://www.studylight.org/lexicons/hebrew/2623.html
At any rate, the usage of the Greek word HOSIOS of Jesus in Acts 2:27; 13:35 does not designate Jesus as being the Supreme Being.
Acts 3:14 - But ye denied the Holy (Strong's #G40) and Righteous One, and asked for a murderer to be granted unto you.
Here we find that Peter used a form of the Greek HAGIOS of Jesus. This word is definitely not confined to being used of the Supreme Being, as it used many times of humans and things in the New Testament.
https://www.studylight.org/lexicons/greek/40.html
Romans 1:4 - who was declared [to be] the Son of God with power, according to the spirit of holiness (Strong's #G42, a form of #G40), by the resurrection from the dead; [even] Jesus Christ our Lord.
https://www.studylight.org/lexicons/greek/42.html
Many claim "spirit of holiness" is referring to God's Holy Spirit. This could be, but one should realize that the word "spirit" in the Bible is not always referring to God's Holy Spirit. The word "spirit" in Romans 1:4 is probably used as may be contrasted with its usage as in the phrases such as "spirit of bondage" (Romans 8:15), "spirit of stupor" (Romans 11:8), "spirit of the world" (1 Corinthians 2:12), "spirit of fearfulness" (2 Timothy 1:7), "spirit of error." -- 1 John 4:6.
Of course, God's Holy Spirit is just as holy and God Himself is Holy. Such, however, does not mean that we need to imagine and assume that God's Holy Spirit is a separate and distinct person of God, etc.
What we do not find in any of the scriptures above is any thought that the God of Abraham, Isaac and Jacob is more than one person, or that Jesus is the God of Abraham, Isaac and Jacob, or that Jesus is a person of the God of Abraham, Isaac and Jacob.