It may be a little easier to understand how it is that Adam could have sinned being that he was tempted by another agent, Satan. However, it may be more difficult to understand why it is that Satan chose sin. Satan was not tempted by anything or anyone else. Some find it problematic and an argument against free will, that is, that there is no reason why Satan would choose sin from the beginning. Satan had to have been determined to sin. I can understand that it is problematic, or unresting, in understanding the first sin, but I would rather understand the first sin as having its origin from the created being. One of the tenets of soft-libertarianism is that all choices are not causally determined but are internally originated from the agent. Causal relations may influence the soft-libertarian agent, but it does not cause him to do anything. I would rather have the trouble explaining/speculating as to why a sinless free agent chose to sin rather than explain/speculate how a holy and perfect being can cause sin. This is just a thought that came up in discussion earlier.
Why Would a Sinless Agent Choose Sin?