This Might Be a Sermon Someday...

Why do church people assume that everything recorded as the spoken words of Jesus were meant to be taken as stand-alone, pithy sayings?

That's what PROVERBS is for!

Aside from the Sermon on the Mount (which only occurs in that form in Matthew's account of Jesus' life, but that's a different discussion), Jesus is seen constantly speaking in CONVERSATION, answering specific questions or rebuking/encouraging specific acts of his disciples or others.

For example, John 14:6 - "Jesus answered, 'I am the way and the truth and the life. No one comes to the Father except through me.'"
Why is it the traditional practice to not mention those first two words when quoting this verse?
Because we might actually need to read the whole chapter, and thus find out what specific QUESTION he was ANSWERING?
That we might need to read the whole conversation, instead of taking a single sentence out of context to justify whatever whenever?

It was in fact a very specific question.
14:5 - "Thomas said to him, 'Lord, we don’t know where you are going, so how can we know the way?'"

Which of course was the result of another statement of Jesus', which has also been stripped of its conversational context and thrown around to justify a whole lot of random dogma and doctrines over the centuries.
14:1-4 - “Do not let your hearts be troubled. You believe in God; believe also in me. My Father’s house has many rooms; if that were not so, would I have told you that I am going there to prepare a place for you? And if I go and prepare a place for you, I will come back and take you to be with me that you also may be where I am. You know the way to the place where I am going.”

This little chunk of text has been misinterpreted to mean:
"I'm going to Heaven, and you'll be coming with me!"
And of course the 14:6 verse has been chained to that interpretation as well to lock Christ down into the us vs. them Greco-Roman version of Christianity which post-dates Christ and everything else included in the Bible by centuries.
The word "house" here is the exact same word Christ uses when running the money-changers out of the temple (John 2:16 - "To those who sold doves he said, 'Get these out of here! Stop turning my Father’s house into a market!'"), yet no one interprets that verse to mean some existential point about the afterlife.

When we only grind individual verses into our children's heads instead of encouraging them to read the surrounding text, examine the person or persons believed to have been responsible for writing the particular book included in the Bible, and so on and so forth in exploring the context, we reduce them to spiritual parrots, or worse, set them up to be platitude-spewing hypocrites later in life.

Especially when we take a one-to-one approach in justifying dogma and doctrine and public policy with verses of scripture.
Which of course is the time-honored tradition of American evangelical leaders, just as it was with European Roman Catholic leaders, just as it is with Middle Eastern Fundamentalist Muslim leaders.

In the words of Dr. Donald A. Carson:
"A text without a context is just a pretext for a proof-text."