Daniel 12:4
4 But thou, O Daniel, shut up the words, and seal the book, even to the time of the end: many shall run to and fro, and knowledge shall be increased. KJV
Our knowledge concerning Biblical languages, Bible manuscripts, and Hebrew culture has increased over the last few centuries, a fact that many who defend the Trinity simply ignore.
When we take the time to research how and when the doctrine of the Trinity was developed we can discern this doctrine is a tradition of men, which should concern those who believe what Jesus said to the Pharisees:
Matthew 15:3-6
3 But he answered and said unto them, Why do ye also transgress the commandment of God by your tradition?
4 For God commanded, saying, Honour thy father and mother: and, He that curseth father or mother, let him die the death.
5 But ye say, Whosoever shall say to his father or his mother, It is a gift, by whatsoever thou mightest be profited by me;
6 And honour not his father or his mother, he shall be free. Thus have ye made the commandment of God of none effect by your tradition. KJV
The traditional acceptance of the doctrine of the Trinity has made the following as well as all the NT Scriptures that tell us that the only wise God is the Father of "none effect" by taking Scripure out of context, ignoring how Hebrew culture understood their own language, and by interpreting Scripture through the lens of Greek philosophy:
Exodus 20:1-6
20:1 Then God spoke all these words, saying,
2 "I am the LORD your God, who brought you out of the land of Egypt, out of the house of slavery.
3 "You shall have no other gods before Me.
4 "You shall not make for yourself an idol, or any likeness of what is in heaven above or on the earth beneath or in the water under the earth. 5 You shall not worship them or serve them; for I, the LORD your God, am a jealous God, visiting the iniquity of the fathers on the children, on the third and the fourth generations of those who hate Me, 6 but showing lovingkindness to thousands, to those who love Me and keep My commandments. NAS