The Christian trinity makes perfect sense

Quoting the "New Testament" does not prove that it is true, for the same reason that quoting the Quran does not prove that Islam is true. When analyzing a supposedly holy book, you must compare it to what was written before, which in this case is the Hebrew Bible (which you call "the Old Testament"). * Isaiah 9 : 5 [6] One can argue that the phrases "Mighty G-d" and "Everlasting Father" cannot be incorporated as part of a man"s name, and therefore Isaiah teaches that the Messiah has to be not only a man, but G-d as well. That this entire reasoning is incorrect may be seen from the name Elihu, "My G-d is He," which refers to an ordinary human being (see 1 Samuel 1 : 1, Job 32 : 2, 1 Chronicles 12 : 20). A similar misunderstanding of Scripture may be seen in claims revolving around the name Immanuel, "G-d is with us." The simple fact is that it is quite common in the Bible for human beings to be given names that have the purpose of declaring or reflecting a particular attribute of G-d, e.g., Eliab, Eliada, Elzaphan, Eliakim, Elisha, Eleazar, Tavel, Gedaliah. So why is "El Gibbor" (Mighty G-d) any different? Isaiah is known for presenting his message through the use of prophetic names (see Isaiah 7 : 3, 8 : 3). In Isaiah 9 : 6 the prophet expounds his message by formulating a prophetic name for Hezekiah. The words of this name form a sentence expressive of Gd's greatness, which will become manifest in the benefits to be bestowed upon the future king in his lifetime. Thus, the name, though borne by the king, serves, in reality, as a testimonial to G-d. Hezekiah is called "a wonderful counselor" because this name is a sign, which foretells G-d's plan to help him save Jerusalem from the Assyrians. (Isaiah 37 : 6-7) "And Isaiah said unto them: "Thus shall ye say to your master: Thus saith the Lord: Be not afraid of the words that thou hast heard, wherewith the servants of the king of Assyria have blasphemed Me. Behold, I will put a spirit in him, and he shall hear a rumour, and shall return unto his own land; and I will cause him to fall by the sword in his own land."" Hezekiah is called "the mighty G-d" because this name is a sign that foretells G-d's defense of Jerusalem through the miraculous sudden mass death of Sancherib"s army. (Isaiah 37 : 33-35) "Therefore thus saith the L-rd concerning the king of Assyria: He shall not come unto this city, nor shoot an arrow there, neither shall he come before it with shield, nor cast a mound against it. By the way that he came, by the same shall he return, and he shall not come unto this city, saith the L-rd. For I will defend this city to save it, for Mine own sake, and for My servant David's sake." Hezekiah is called "the everlasting Father" because this name is a sign, which foretells that G-d will add years to his life. (Isaiah 38 : 5) ""Go, and say to Hezekiah: Thus saith the L-rd, the G-d of David thy father: I have heard thy prayer, I have seen thy tears; behold, I will add unto thy days fifteen years."" Hezekiah is called "the ruler of peace" because this name is a sign, which foretells that G-d would be merciful to him. Punishment for lack of faith in the Almighty will be deferred and peace granted during the last years of his rule. (Isaiah 39 : 8) "Then said Hezekiah unto Isaiah: "Good is the word of the L-rd which thou hast spoken.' He said moreover: 'If but there shall be peace and truth in my days."" * The Hebrew Bible does mention the Holy Spirit, and it does refer to G-d as the Father, but this does not prove that G-d is divided into three, and it does not prove that Jesus is part of the trinity. If G-d were divided into three, it would mean that each of those three sections is limited. This contradicts the fundamental principle of all Abrahamic religions: Gd is unlimited because he is the creator of all limitations, and he is not subject to the laws of his own creation. * It seems that even the authors of the New Testament did not believe in any trinity. (Matthew 27:46) "And about the ninth hour Jesus cried with a loud voice, saying, Eli, Eli, lama sabachthani? that is to say, My G-d, my G-d, why hast thou forsaken me?" To who is he speaking? If he is G-d, it would mean that he is speaking to himself. If Jesus is G-d, why would he even ask the question? He should know the answer. The Hebrew Bible is very clear that G-d is not a man (Numbers 23:19, Hosea 11:9).