There is one body, and one Spirit, even as ye are called in one hope of your calling
As late as Acts 26 Paul testified, "Having therefore obtained help of God, I continue unto this day, witnessing both to small and great, saying none other things than those which the prophets and Moses did say should come." NONE. Yet Ephesians speaks of a truth hidden from the prophets from before the foundation of the ages and revealed to Paul alone. Again... if people want to mash it all together, good luck. I say, feel free to try and practice ALL these things together. No skin off my nose.
People are free to pretend they take all scripture for themselves, but they clearly don't (and that is easily demonstrated). I'm not here to convince anyone. If somebody thinks all the commands and conditions of scripture are for all people of all ages, have at it. Clearly some practices and commands contradict others (if we assume all scripture is to all people). But I am not the judge of another man's servant. But, please, if you're going to claim that ALL scripture is to you and for you, then you're going to have to explain some things.
Here's an easy one... BIBLE COMMAND: build a boat of gopher wood, with one door, and pitch it in and out with pitch because a worldwide flood is coming. BIBLE COMMAND! Good luck. Not to me. How do I know? No flood coming. Commands and conditions do not apply in this age. Does the one who claims ALL of scripture is TO him believe he should build an ark for a coming judgment of a worldwide flood? I've never met anyone building an ark, but I've met a lot of people who claim I'm "tearing out parts of the Bible" because I do not believe all of it is spoken TO me.
Do these folks take a sacrifice to Jerusalem for the Feasts? Why not? Do they perform miracles? Do they avoid the Tree of Knowledge? Do they walk around naked? Do they preach to Jews that God will restore all things if they repent? Do they give only gentile believers "four necessary things" to obey? Do they start their preaching in Jerusalem? Do they only speak that which Moses and the Prophets promised? Do they warn gentile believers they will be cut off from Israel if they become haughty against that root? Etc...
Even Mark 16 should be a clue that conditions have changed since the gospel/Acts age (and that's mild compared to the myriads of other commands and practices of scripture). But, again, folks are free to try and "obey" everything they read. Good luck!
Consequently they know little or nothing of other callings and imagine that God's plans revolve solely around themselves. This is a species of slavery to self that we all need to be delivered from.