The Fallacy of "God Wouldn't Let Me (____________)"

There are two basic ways we can try to avoid responsibility for our actions, and they are summarized in the following formats:

The devil made me do it.  

God wouldn't let me do it, if He didn't want it to happen.  

I believe both of these formats circumvent agency and are not consistent with Mormon theology. 

As to the second phrasing, the one we tend to hear more within our own faith community, it is no different than if a child said:

My parents wanted me to have a cookie, or they would have put the jar in a place where I couldn't get to it.

At some point, we need to stop being merely children of God, grow up and become adults/heirs of God.