A baptism of fire was a soldier's first experience of shooting. Any unpleasant experience undergone, usually where it is also a learning experience, is a baptism of fire.
A belief in the hereafter is a belief in the afterlife, or life after death. It is, therefore, associated with religions and the soul's journey to heaven or to hell, whichever way being just deserts for the person based on how they led their life.
This is the shortened form of the full idiom, 'better the devil you know than the devil you don't', and means that it is often better to deal with someone or something you are familiar with and know, even if they are not ideal, than take a risk with an unknown person or thing.
When people say that the devil finds work for idle hands, they mean that if people don't have anything to do with their time, they are more likely to get involved in trouble and criminality.
When people say that the devil in the detail, they mean that small things in plans and schemes that are often overlooked can cause serious problems later on.
Pertains to the ability to accomplish a task or meet an obligation, barring unforseen complications. Example: "I will be at work tomorrow, Lord willing and the creek don't rise."
This expression indicates a person's determined intention of getting a work done in spite of all odds he may face. He will use all and every means to accomplish the target. Example: He moved heaven and earth to get his literary work recognised by the committee of experts.
In Dante's Inferno, the ninth circle of hell is the centre where the worst punishments are found, so it is used idiomatically for something that couldn't get worse.
If someone is given a poisoned chalice, they are given a job or task which appears attractive but is actually doomed to failure or beset with problems that will damage their reputation or harm them.