Your Personal Opinion May Have No Bearing
Whatsoever On Doctrinal Truth...

Let us first look at some basic definitions using the Greek roots of words from which they came.
1. Philosophy: 'Philo' from the Greek root, 'Philos' means "the love of". 'Sophy' from the Greek means 'wisdom'.
So philosophy simply means the love of wisdom.
2. Orthodoxy: 'Ortho' from the Greek 'orthos' means straight, or correct. 'Doxa' means 'opinion'. So orthodoxy means a 'straight opinion', or in a simpler analogy, the truth.
3.  Now if we combine the word 'philo' with the Greek root word 'doxa' we get the word 'philodoxy'.
So as the great Greek philosopher Plato, proclaimed, the word 'philodoxy' was the opposite or antonym of the word philosophy.
4. To add to what we have learned from this simple lesson is that a philosopher is a lover of wisdom, whereas a philodoxer is a lover of opinion.

"Teacher, we know that you are a truthful man and that you are not concerned with anyoneís opinion. You do not regard a personís status but teach the way of God in accordance with the truth."
Mark 12:14 (NAB)

They sent their disciples to him, with the Herodians, saying, "Teacher, we know that you are a truthful man and that you teach the way of God in accordance with the truth. And you are not concerned with anyoneís opinion, for you do not regard a personís status."
Matthew 22:16

They posed this question to him, "Teacher, we know that what you say and teach is correct, and you show no partiality, but teach the way of God in accordance with the truth."
Luke 20:21

Jesus did not accept the opinions of men, as shown in Matthew 16:13-17:
When Jesus went into the region of Caesarea Philippi he asked his disciples,
"Who do people say that the Son of Man is?"
They replied, "Some say John the Baptist, others Elijah, still others Jeremiah or one of the prophets."
He said to them, "But who do you say that I am?"
Simon Peter said in reply, "You are the Messiah, the Son of the living God."
Jesus said to him in reply, "Blessed are you, Simon son of Jonah. For flesh and blood has not revealed this to you, but my heavenly Father."

See? His disciples mostly expressed personal opinions, which meant little to Jesus.
The one exception was Simon Peter, the only one who answered with doctrinal truth.

 "And if you invoke as Father him who judges each one impartially according to his deeds, conduct yourselves with fear throughout the time of your exile."
1Pet 1:17

"In rendering judgment, do not consider who a person is; give ear to the lowly and to the great alike, fearing no man, for judgment is Godís. Refer to me any case that is too hard for you and I will hear it."
Deut 1:17

"For the LORD, your God, is the God of gods, the LORD of lords, the great God, mighty and awesome, who has no favorites, accepts no bribes;"
Deut 10:17

"And now, let the fear of the LORD be upon you. Act carefully, for with the LORD, our God there is no injustice, no partiality, no bribe-taking."
2Chron 19:7

"There is no partiality with God."
Rom 2:11

"Masters, act in the same way toward them, and stop bullying, knowing that both they and you have a Master in heaven and that with him there is no partiality."
Eph 6:9

"For the wrongdoer will receive recompense for the wrong he committed, and there is no partiality."
Col 3:25

"My brothers, show no partiality as you adhere to the faith in our glorious Lord Jesus Christ."
Jam 2:1

There are three sides to every dispute, side A, side B, and the one side of truth.
Everyone is entitled to their own opinion, but opinions are just that,
and are not to be taken as a substitute or stand-in for doctrinal truth.

Then Peter proceeded to speak and said, "In truth, I see that God shows no partiality."
Acts 10:34

"What is Truth?"
John 18:38 

There is only
one truth, and that one truth is one person, the person of Jesus Christ.
In John 14:6, Jesus said, "I am the way, the truth and the life
Therefore, we have only
one teacher, and one truth.

What does Holy Scripture tell us about speaking the truth?

"But the king said to him, "How many times shall I adjure you that you speak to me
nothing but the truth in the name of the LORD?""
1King 22:16, 2Chron 18:15

"The LORD is near to all who call upon him, to all who call upon him in truth."
Psa 145:18

"He who speaks the truth gives honest evidence, but a false witness utters deceit."
Prov 12:17

"These are the things that you shall do: Speak the truth to one another,
render in your gates judgments that are true and make for peace."
Zech 8:16

God is spirit, and those who worship him must worship in spirit and truth."
John 4:24

You are of your father the devil, and your will is to do your father's desires. He was a murderer from the beginning, and has nothing to do with the truth, because there is no truth in him. When he lies, he speaks according to his own nature, for he is a liar and the father of lies."
John 8:44

And I will pray the Father, and He will give you another Counselor, to be with you forever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him; you know him, for he dwells with you, and will be in you."
John 14:16-17

Sanctify them in the truth; thy word is truth."
John 17:17
That verse is interesting because with it we can refer to another verse which defined the Word:
John 1:1 "In the beginning was the Word, and the Word was with God, and the Word was God."

"For the wrath of God is revealed from heaven against all ungodliness and wickedness
of men who by their wickedness suppress the truth."
Rom 1:18

"They exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator,
who is blessed for ever! Amen."
Rom 1:25

"...but for those who are factious (opinionated maybe?) and do not obey the truth, but obey wickedness, there will be wrath and fury."
Rom 2:8

"We have renounced disgraceful, underhanded ways; we refuse to practice cunning or to tamper with God's word, but by the open statement of the truth we would commend ourselves to every man's conscience in the sight of God."
2Cor 4:2

"For we cannot do anything against the truth, but only for the truth."
2Cor 13:8

"Have I then become your enemy by telling you the truth?"
Gal 4:16

"You search the scriptures, because you think you have eternal life through them; even they testify on my behalf.
But you do not want to come to me to have life. I do not accept human praise; moreover, I know that you do not have the love of God in you. I came in the name of my Father, but you do not accept me; yet if another comes in his own name, you will accept him. How can you believe, when you accept praise from one another and do not seek the praise that comes from the only God?"
John 5:39-44

"In giving this instruction, I do not praise the fact that your meetings are doing more harm than good.
First of all, I hear that when you meet as a church there are divisions among you (the end result of differing opinions), and to a degree I believe it; there have to be factions among you in order that those who are approved (those who have the truth) among you may become known. When you meet in one place, then, it is not to eat the Lordís supper, for in eating, each one goes ahead with his own supper, and one goes hungry while another gets drunk. Do you not have houses in which you can eat and drink? Or do you show contempt for the church (note a singular Church) of God and make those who have nothing feel ashamed? What can I say to you? Shall I praise you? In this matter I do not praise you."
1Cor 11: 17-22

"They hate him who reproves in the gate, and they abhor him who speaks the truth."
Amos 5:10

"The coming of the lawless one by the activity of Satan will be with all power and with pretended signs and wonders, and with all wicked deception for those who are to perish, because they refused to love the truth and so be saved. Therefore God sends upon them a strong delusion, to make them believe what is false, so that all may be condemned who did not believe the truth but had pleasure in unrighteousness."
2Thess 2:9-12 

"This is good, and it is acceptable in the sight of God our Savior, who desires all men to be saved and to come to the knowledge of the truth."
1Tim 2:3-4

"If I am delayed, you may know how one ought to behave in the household of God, which is the church of the living God, the pillar and bulwark of the truth."
1Tim 3:15
"If any one teaches otherwise and does not agree with the sound words of our Lord Jesus Christ and the teaching which accords with godliness, he is puffed up with conceit, he knows nothing; he has a morbid craving for controversy and for disputes about words, which produce envy, dissension, slander, base suspicions, and wrangling among men who are depraved in mind and bereft of the truth, imagining that godliness is a means of gain. There is great gain in godliness with contentment;"
1Tim 6:3-6

"But you must remember, beloved, the predictions of the apostles of our Lord Jesus Christ; they said to you, "In the last time there will be scoffers, following their own ungodly passions." It is these who set up divisions, worldly people, devoid of the Spirit. But you, beloved, remember the words spoken beforehand by the apostles of our Lord Jesus Christ, for they told you, "In (the) last time there will be scoffers who will live according to their own godless desires." These are the ones who cause divisions; they live on the natural plane, devoid of the Spirit."
Jude 1:17-19

Why are there so many differences of opinion among those who read the same verses?
One reason is because each person has a built in filtering system. What we hear enters the ear,  and what we read enters the eye, and both are filtered by the brain and stored. Since each person is a unique human being, these filtering systems can vary from person to person. What one interprets after it is filtered can be different from what another interprets, thus a difference of opinion results. Let us take a look at some typical verses as examples of opinionated filtering systems:

1. "All have sinned", Rom 3:23

A. The fundamentalist would take this verse literally as he reads his English translation of the bible. He would say by the use of the word "all", it surely means just that, everyone who has ever lived has sinned. There is no doubt about it.
B. Another person, knowing that this verse was not written in English, but in Greek, might question the English translation for using the word "all" from the Greek word "pas*". His filter system has brought him to the conclusion that it could not mean everyone, but "a great many". After all, he reasons, did Jesus sin? Have babies sinned? Can a comatose person sin? He has come to the conclusion that since he has found three exceptions to the word "all", might there not be more?
So, have all really sinned?
Which one has the correct opinion if either? In this example it is seen that where there is a translation from one language to another, there could be variations in the meaning of the verse.
*The Greek word Pas, indeed can mean 'a great many', or 'any'.

2. "So Jesus said to them, "
Truly, truly, I say to you, unless you eat the flesh of the Son of man and drink his blood, you have no life in you;" John 6:53

A. The fundamentalist, who takes almost the whole Bible literally, would drop the literal translation of that verse in favor of an opinionated symbolic translation. He uses eisegesis which means, reading into a text something that simply is not there. In no way did Jesus say that he was speaking symbolically.
B. The other person, knowing that it was said by "truth" Himself would take the verse literally. Jesus said it, therefore it has to be true.

So, which interpretation of that verse is the true interpretation? The fundamentalist would say that Scripture is clear and is easily interpreted.
Well if Scripture is so clear, then why are there so many differences of opinion as to its interpretation? And not only that, but why does Scripture itself say that it is not clear?
"So also our beloved brother Paul wrote to you according to the wisdom given him, speaking of this as he does in all his letters. There are some things in them hard to understand, which the ignorant and unstable twist to their own destruction, as they do the other scriptures."
2Pet 3:15-16 

In this little exercise with the examples presented, you can readily see how personal opinions can make accurate study of Holy Scripture problematic, and can be the root cause of division.

So what is the answer regarding personal opinions? How can we determine which one has doctrinal truth, and which one is merely expressing a misguided personal opinion?
We can be sure by having only
one authority, bestowed by GOD, to separate what is truth from what is error. Read Matthew 16:13-17 again, for the perfect Biblical example of personal opinions of men versus doctrinal truth given by GOD to the one and only Simon Peter.

"What is truth comes from GOD. What is false comes from man."
Archbishop Fulton J. Sheen

"Trust in the Lord with all your heart, and do not rely on your own understanding."
Proverbs 3:5

"A fool takes no pleasure in understanding, but only in expressing his opinion."
Proverbs 18:2