The fellowship of life is preserved, safeguarded, protected, by the sense of life. Even with our physical body it is the same. Our feelings of pain or discomfort are a protection and a safeguard to us. Thus, to realize the fellowship of life and to safeguard, keep, and preserve the fellowship of life are all by the sense of life.
Our relationship of life with the Father can never be broken but the fellowship can be broken. The breaking of the fellowship of life is like the breaking of the electrical current. Even a small thing can cut off the electricity, and this breaks the electrical current.
The breaking of the fellowship of life is first by sins. If we do something which we know is sinful, this breaks, cuts off, the fellowship of life.
If we disobey God, this surely cuts off the fellowship of life.
We must care for the sense of life. If we do not care for it, this will break the fellowship of life.
The main things that generally cut off the fellowship of life are sins, disobedience, not caring for the sense of life, and not following the inner anointing. First John 2:27 says clearly that we have to abide in the Lord according to the teaching of the anointing.