Here's a rhetorical question...

First, a confession...

I read and mark up books of the Apocrypha like I do Scripture or a good book.

My daughter and I were discussing something this morning that she was passionate enough to be in tears over and I found myself reading her an excerpt from the Apocrypha.

One thing led to another and we were discussing the origins of the Bible. That led to this question...

Why do we spend more time reading and preaching from biographies and letters contained in the New Testament, rather than the books of the Old Testament which the New Testament writers referred to as Scripture?

Look at these New Testament references.

"He who believes in Me, as the Scripture has said..."

(John 7:38)

"...From childhood you have known the sacred writings 

Which are able to give you the wisdom 

That leads to salvation 

Through faith which is in Christ Jesus. 

All scripture [is] given by inspiration of God, 

And [is] profitable for doctrine, 

For reproof, 

For correction, 

For instruction in righteousness."

(2 Timothy 3:14-16)

Noah Webster defined 'Scripture' as, 'In its primary sense, a writing; any thing written.'

In this sense, Paul's writings were scripture as they were written (2 Peter 3:15-17). 

But when Paul alluded to 'Scripture', he wasn't talking about himself.

But, here's the problem, people have created and continue to support doctrines using New Testament passages alone?

Christ Himself read from Isaiah to reveal who he was (Luke 4:17) 

Also, as recorded in Luke 24:27,

"beginning with Moses and all the prophets, he interpreted to them the things written about himself in all the scriptures.

"For whatsoever things were written aforetime 

Were written for our learning, 

That we through patience and comfort of the Scriptures 

Might have hope."

(Romans 15:4)

In the previous passage, Paul was telling the Christians in Rome to find comfort in the Scriptures. 
However, we, in the 21st century, find our comfort almost entirely from Paul's letters?

You know what this sounds like?
It would be like me staring at a scrap of paper on which are scribbled directions to the grocery store in order to fill my frig.

Reading inspired books can be profitable.
Supposedly Martin Luther even condoned reading the Apocrypha.

"...Apocrypha, that are books which are not considered equal to the Holy Scriptures, but are useful and good to read."
---Martin Luther

Why are some christians today so passionately defensive of a particular translation or even of the standard for 'Scripture' set by the The Council of Nicaea?
This council was literally a church fight.  

In fact, a bishop actually punched a presbyter and was later himself canonized. What!?
And this leadership dictated what is now worshiped as truth (doctrinal explanations,  the creed, the New Testament, etc.)?

If this had been reported in today's news and a religious big name punched the guy who disagreed with him and then he and his peers set up their own interpretations of heresy, would you be on board?
Most of us are, whether we know it or not.

Personally, I don't fully agree with either side that was arguing. They shouldn't have been doing it in the first place, according to Paul.

"AS FOR the man who is a weak believer, 

Welcome him [into your fellowship], 

But not to criticize his opinions 

Or pass judgment on his scruples 

Or perplex him with discussions." 

(Romans 14:1)

"Remind the people of these facts 

And solemnly charge them in the presence of the Lord 

To avoid petty controversy over words, 

Which does no good but upsets 

And undermines the faith of the hearers."

(2 Timothy 2:14)

In today's churches, quotes from Paul are used to support twisted interpretations of Paul!

People in leadership are preaching twisted doctrines using misinterpretations of Paul's letters who, according to the same letters they claim to source, ought not to even be in leadership OR service of the church at all due to the condition of their children or state of their marriage.

Peter talked about the distortion of Paul's letters less than 50 years after Christianity had begun!

"...Paul also wrote to you 

According to the spiritual insight given him...

As he does in all of his letters. 

There are some things in those epistles of Paul 

That are difficult to understand, 

Which the ignorant and unstable twist 

And misconstrue 

To their own utter destruction, 

Just as they distort and misinterpret the rest of the Scriptures. 

Let me warn you therefore, beloved, 

That knowing these things beforehand, 

You should be on your guard, 

Lest you be carried away by the error of lawless...

And fall from your own present firm condition 

Your own steadfastness of mind."

(2 Peter 3:15-17 AMP)

There are an awful lot of Law-LESS 'christians' in our churches. 
There are even more who have little to no familiarity with the whole of Scripture... that to which Peter and Paul referred.

Consider this...
Within the 'Bible' which that fighting bunch of 'christians' canonized in AD 325 is the accepted letter of Jude.
From Jude 1:14-16,

"It was of these people, moreover, that Enoch in the seventh generation from Adam prophesied when he said,
Behold, the Lord comes with His myriads of holy ones to execute judgment upon all and to convict all the impious (unholy ones) of all their ungodly deeds which they have committed in such an ungodly way, and of all the severe things which ungodly sinners have spoken against Him.
These are inveterate murmurers (grumblers) who complain of their lot in life, going after their own desires controlled by their passions; their talk is boastful and arrogant, and they claim to admire men's persons and pay people flattering compliments to gain advantage."

Where is that book of Enoch?

Consider this verse of Scripture,

"My people are destroyed for lack of knowledge..."
(Hosea 4:6 AMP)

..."impious ones"

..."unholy deeds"

..."ungodly way"

..."complain about their lot in life"

..."going after their own desires"

..."controlled by their own passions"

..."talk is boastful and arrogant"

..."admire men's persons"

..."pay people flattering compliments to gain advantage"

(Um...that sounds like the conditions surrounding conflicts I have unfortunately witnessed)

If the Council of Nicaea squabble was happening today, would you throw your lot in with the violent and abusive party?
Most did... and still do.
Many worship the Bible rather than the Creator.
The blind lead the blind.
People believe the way they always believed and practice what supports either their appetites or self-righteousness.

How is this any better than other religions?

Believing Jesus truly IS the difference in Christianity... that is,  IF you haven't just tweaked His words to fit a way of thinking you are now comfortable with.

"Now... 

What does the LORD your God require from you, 

But to fear the LORD your God, 

To walk in all His ways and love Him, 

And to serve the LORD your God 

With all your heart and with all your soul."

(Deuteronomy 10:12)

"Pure and undefiled religion 

In the sight of our God and Father is this: 

To visit orphans and widows in their distress, 

And to keep oneself unstained by the world."

(James 1:27)

Stand up Shepherds!
Division is bound to happen if only to know which sheep are genuine.
...and the majority side of the split is not likely the genuine and approved ones fit for the service of the Lord.

1 Corinthians 11:18-19,
"...When you assemble as a congregation, I hear that there are cliques (divisions and factions) among you; and I in part believe it,
For doubtless there have to be factions or parties among you in order that they who are genuine and of approved fitness may become evident and plainly recognized among you."