Why do you believe in Sola Scriptura?
This is probably better answered through more general apologetics. Upfront I'll stay that I don't view religion as being so compartmentalized but for this sake of explanation, I'll break it down for you in chunks. Probably nothing new here for you and I'm sure there are more formal and standardized terms but I'm separating Christianity into two parts (though there's overlap), 1). one's relationship to God and 2). one's relationship with fellow humanity.
One's relationship with God could be described as the vertical, human on earth, God above human in heaven. (Mind you, this description is for diagram purposes only). The vertical relationship w/God is cultivated through such acts as praying, reading the Bible, singing praises, fasting. If you look at the ten commandments, the first half (not 5 but part) have to do with the vertical relation,
No other Gods before Me, no false idols, don't take Lord's name in vain. Same as the first half of the Lord's prayer,
Hallowed be Thy name...Your will on earth. Jesus even has a convo w/someone about the most important commandments - the answers: Love the Lord w/all your heart and #2 Love your neighbor as yourself. Which brings me to the horizontal relationship
The second way Christ's love is perfected w/in Christians is through their relationships with other people. (Some people like to diagram this using a cross to symbolize both). Such activities as going to church, loving your enemies, remembering the needs of the poor, correcting or encouraging members of the body, seeking justice, serving others in humble submission are required by God. Jesus talks about before you give your big assed check in the offering plate (something on the vertical tip), settle that feud you've been having with your neighbor (horizontal yo).
One has to look out for others but
works alone won't do it. That said, getting closer to God isn't just a bunch of rules being followed or deeds to get gold stars, it is a lifelong process, often a struggle. If you look at
Jacob, Jeremiah, Joseph, Jonah, Job, Elijah (see, not all J's), Mary, Mary Magdalene, Paul, the rich young ruler, Abraham, Moses, David, Peter, the list doesn't end, they all had their struggle in coming to understanding. This struggle isn't random nor a matter of weakness but
essential in developing faith and growing in the Lord.
Why I believe in Sola Scriptura is that it allows and encourages understanding without there being anyone to interfere with the vertical relationship between God and human. It's not that we all have to find our own truth but that we each need to
cultivate our relationships w/God on our own. And it certainly does not negate the importance of preachers, teachers and shepherds of the body.
John 1:1-4 & 14
1In the beginning was the Word, and the Word was with God, and the Word was God. 2He was in the beginning with God.
3All things came into being through Him, and apart from Him nothing came into being that has come into being.
4In Him was life, and the life was the Light of men.
...
14And the Word became flesh, and dwelt among us, and we saw His glory, glory as of the only begotten from the Father, full of grace and truth.
For those who take that the essence of God existed before creation and assisted in creation as true, couple that with the belief that Jesus' sacrifice on the cross removed the barrier between humanity and God, I think it makes sense to believe the Bible is it's own authority and that one does not have to go through man to get its meaning or to authenticate it - which, if I'm not mistaken falls under the definition of Sola Scrutura, no?
I can't imagine that if Christ came to earth as a man so that
all of humanity could live eternally with God that that same God who freely gave His Spirit to dwell within faithful believers would then only allow the meaning of His essence to be grasped by a tiny, select few or possibly only one person on earth, such as the case of ex cathedra. My complaint and it's not strictly against the Catholic church because it happens in different forms elsewhere but I vehemently oppose any human (either themselves or their invented regulations) trying to place themselves as a go-betweens or gate keepers or mediators between people on earth and God in heaven. My belief is there should be no one in the vertical plane between God in heaven and humanity on earth.