Jesus..
= He came to the "House of Israel"... not to the gentiles.
So, Jesus was a Jew, born under the law, and His ministry was to the JEWS, who were OT= under the law.
His Teaching, (usually)( unless its prophetic, such as you find in Matt 24),.....was all given to the JEWS......."under the Law">, as if Jesus was talking to them in Isaiah's day.
Now..........When the NT was created, long after Jesus was back in GLORY...., they put in the Gospels, and Paul's epistles, and so forth, and called it the NT.
The NT, is actually the Sacrifice and Death, and Resurrection, of Jesus, that is the New Covenant.
JESUS is the New Testament and its written in His Blood.
The word of God that is the NT, talks about this using scripture.
So, when we read in the Bible, in the NT, .. something that Jesus told to OT Jews, under the Law... that is not all of them suddenly becoming the NT CHURCH, simply because you find the verse in the New Testament.
Its Jesus the Jew, under the Law, talking to OT Jews, under the Law, ......and much of what He says to them, is not applicable to the Body of Christ that is the "Church", who are mostly Gentiles., and are "not under the Law, but under GRACE"....
Thus....The Reason that Paul told the believers, to "rightly divide the word"... is because, when we have scriptures, and some are talking to unsaved Jews, when Jesus was on the Earth.... VS.... what Paul teaches, to the Church, that Jesus gave to Paul for the BODY of CHRIST.....
See that DIVISION?
Those are not the same........so, when a person is trying to apply to the Church some Verse that is directed by Jesus the Jew, to Jews who are under Moses Law, then you end up with 45,000 Denominations worldwide, that all DISAGREE.
You also find this same confused type of person on forums and in pulpits, who thinks....>>"oh, its all bible, so its all the same...
No, ... its not.
= 45,000 Denominations world wide.
= Endless fighting on Forums.