Lane clearly believes that we should base our decision making on a standard outside ourselves. That standard is what God wants us to do.
Lane talks about all the ways in which people rationalize that it is okay for them to have sex outside of marriage. These are instances of people looking to themselves as a basis for their decision making. According to Lane, these people are asking what they themselves want, not what God wants.
Instead of doing this, we need to look to God's standards. We have to realize that God has only one plan for sex--that it should be part of marriage. As Lane says
When making decisions, instead of using anecdotes, we need to base our decisions on a standard outside of ourselves.