INTERPOLATION
This name is given to the additions made to an original text by some ancient copyist.
In the Bible they are extremely infrequent and practically unimportant.
Textual criticism in the comparison of numerous mss. ancient NT data from different geographical areas and transmission lines has allowed us to determine, for example, that the second part of Ro. 8:1 is an interpolation: “those who walk not after the flesh, but after the Spirit.”
So, actually, Rom. 8:1 has an unconditional character. This salvation corresponds to a walk, which is what is considered in the following verses.