Do You Believe Me? Holiness

Beginning in 1 Peter 1:16, we see God's call to holiness; yet the perspective is not something we must attain to, but rather something that we are.
But in being holy, we, as humans fall into sin? How does this relate to our walk in Christ, what are we to do?
We see ways that we normally respond, followed by the one way we are all to respond.