"Evil conscience" refers to a person's inner voice or feeling that continuously reminds them of moral wrongdoings or bad actions they have committed. It represents a sense of guilt or remorse that the person feels because they are aware that what they did was not morally right.
Full definition
You shall not go to prayer with
an evil conscience.
If a human can know the dictate of reason, «I ought not commit suicide», through reason — apart from faith — then how can
an evil conscience be the absence of faith?