Does it say in the Bible that we, the common people, are not to interpet the scriptures ourselves?
no, it does not. neither does the church.
the church says that we must read the bible prayerfully and ask the holy spirit to give us understanding
Also, does it say in the Bible than only the Church can interpet scripture correctly?
no, it does not. anyone lead by the holy spirit can interpret correctly. the bible does say that the church (majesterial authority) will infallibly interpret scripture.
jesus said: whatever you bind on earth wil be bound in heaven and whatever you lose on earth shall be loosed in heaven (mt,16:18; mt,18:18)
he also said: he who rejects, you rejects me; and he who rejects me, rejects the one who sent me
this power to infallibly interpret and guide the flock of christ has been passed on through ordination from the apostles to their successors all the way till today
is this necessary?
YES!!!
history has shown that a lot of people can believe that they are being led by the holy spirit in their understanding of the bible. yet, they often end up with totally contrasting views. that’s like saying the holy spirit teaches one man something and another the very opposite (and that is impossible).
so that there might be no confusion or disunity, a central authority set up by divine mandate is required; and that is what we have in the majesterial authority of the church
Where does the Holy Spirit come into all this
the holy spirit was jesus’ guarantee to the apostles. he would “lead them into all truth”
thus, the infallibilty of the majesterium (ex cathedra) is ensured by the holy spirit
can He be relied on for help understanding the scriptures?
he can certainly be relied on. what we can’t rely on is our own understanding (lean not on your understanding…).
unfortunately, we may easily be misled by our own heart into believing that we are hearing the voice of god (the heart is decietful above all things…)
thus, an external authority is required to ensure that the prayer of jesus may come true (that they may be one…)
hope this helps