Faults are like systemic foundational weaknesses and lies that undermine our life and cause repeated sinning. They are often well hidden except for the surface symptoms which may not be obviously the same as the original cause.
To map out a fault line takes a caring community guided by the Holy Spirit. Others can see our blind spots and help us see what we cannot if we will humble ourselves. But only the Holy Spirit can bring true conviction without condemnation. Even then our own heart may condemn us, but this too is symptomatic of an underlying fault line that needs healing.
Faults are areas in our heart and emotions where there is a lack of correct bonding. Fear bonds are unstable and faulty by nature. Only truth and love can repair a deep fault line by cementing our hearts with peace and bonding us securely to God and other believers with joy.