Well I say good then, go ahead get frustrated. Shouldn't life be natural? Shouldn't we know how to live because we know who we are?
Think about it this way. I was born as a female. I started out as a baby girl that then grew into a woman. All my life I knew I was a girl and all my life nature dictated to me I was a girl. I don't recall stopping to think about how to act as a girl. I just learned to live from how I was created to live. Although I must admit, there were times I needed to understand things about being a girl, such as what was happening to my body as I matured. I didn't start out mature as a woman. I grew into a woman, learning along the way. I still will be maturing into the woman I will become. My identity is wrapped up in the fact that I am a woman and I live from that reality.
So how does this relate to being a chrisitian you say? My identity is how I live. I no longer live out of a mentality of good vs. evil, right vs. wrong to be secure in who I am. I live simply from who I already am. I am a new creation in Christ. I identify as Christ.
But here's the trick. I think we get so hung up on understanding this and freely living out of our new identity because we aren't used to our new identity.
Picture it this way. I am born into this world in Adam. Spiritually dead, and living out of the knowledge of good and evil instead of life. I live a significant portion of my life this way, then one day I experience a transformation when I believe in Jesus. This transformation takes away my old nature in Adam, that was spiritually dead and gives me a new life that is spiritually alive in Christ. So I go from being in Adam to in Christ, just by believing in Jesus. Wow! But, what happens when I go from one way of life, to a new way of life. Well, I wonder what now, how do I live? I went from depending on who I was to needing to realize who I now am.
Life as I know it has completely shifted and I am now in the tricky place of learning to live out of my new life. But over time there is a shift, and I begin to learn to live from who I am. Oh, it's not without plenty of reminding myself of the fact that I am a totally new person though. As time goes, my identity remains and I grow into the fullness of who I am. Just like as a little girl grows into a full grown woman.
I am not sure if this analogy is the absolute best to portray my point, but perhaps you catch my drift.............You see as believers, life as we now know it is simply living out of who we have become in Christ.