"Everything happens for a reason." Or, that is what we tell ourselves so we feel less responsible for the decisions we make and the associated consequences. Or to feel that there is some control in an out of control world. The idea that we are responsible for the experience of our existence is overwhelming, so we need a "God" or a "high being" to take this responsibility for us. We create that. It's like a psychological coping mechanism to protect ourselves from reality.
We say that this person will have God to answer to because the idea of having no justice is too much to handle. When in reality, there is no justice. It makes us feel better to think that somehow there will be justice. In reality, there won't be. We create the idea that they will have someone to answer to, it is a coping mechanism and to protect ourselves from the never ending thoughts about injustices. It takes the responsibility to change unethical things off our our shoulders and onto a "God's".