I'm on my way to bed and just wanted to shoot this off so I don't forget it later. In other words, it won't be long. I might add to it some other time.
I don't like the word 'doctrine'. It sounds dead, irrelevant, obsolete, and unrelatable in our modern and post-modern world. But it's still a word so I'll use it.
There are biblical and relevant doctrines of 'spiritual covering'. There are also unbiblical teachings and doctrines of the same. Many people have misused the doctrine and harmed others along the way. An example of the misuse of this doctrine was the Shepherding/Discipleship Movement which was meant to address immaturity in the churches but ended up dominating and suffocating the people it was supposed to help into maturity.
Like other relevant doctrines that many christians have abandoned due to their misuses and abuses, many christians don't believe that spiritual covering is biblical or relevant. But everything that God created is good when done healthily. In the Godhead, you can see the principle of spiritual covering. The Bible also says that God covers Jesus who then covers a husband who then covers his wife. The Bible, both OT and NT, allude to and reference spiritual covering often. So, according to the Bible, what is spiritual covering and why is it important? Allude.
There have to be a bunch of answers to that question. For now, I'll only say that:
1. Spiritual covering isn't your pastor, minister, or someone else who calls themselves your covering. It isn't a label; it is an actual and literal function that has actual effects-- good or bad-- in a person's life.
2. Spiritual covering is anyone who [passively] has responsibility for or [actively, intentionally] takes responsibility for another person.
The a.) person who even against their will is given responsibility for someone else and the b.) person who willingly takes responsibility for someone else are both recognized-- at least in the spirit realm where they see things as they in fact are-- as that person's spiritual covering. They don't have to know it and they don't have to know that it makes any difference or how it works. It just happens as soon as the exchange or agreement happens and as long as it continues.
One of the reasons biblical and legitimate spiritual covering is important to the believer and among believers is because of a.) the many blessings and b.) the increased protection from harm that are available under spiritual covering that are not available without it. Anyone who has some insight or opinions on this topic feel free to chime in.