The criterion for the open sinner whose testimony is not accepted

Question:
Honorable Shaykh, may Allah preserve you, what is the criterion for the open sinner whose testimony is not accepted, who is a Muslim that performs the prayer and testifies to the two testimonies of faith?

Answer:
The Muslim open sinner, or the believer who is an open sinner, is the one who committed a major sin from among the major sins, other than shirk (associating partners with Allah). This open sinner is like one who commits zina (unlawful sexual intercourse), theft, drinking khamr (intoxicants), or qadhf (falsely accusing someone of zina)—specifically, falsely accusing chaste, believing women who are unaware of the accusation. This is the open sinner who committed a major sin that does not entail kufr (disbelief). This is called the believer who is an open sinner, or the believer whose faith is deficient, according to the people of the Sunnah and the community. Yes.