Let me offer a little different perspective.
In some regards, I donât particularly CARE if an NFP method is âeffectiveâ, because it often encourages an attitude that WE control when we are given the GIFT of a child. The Church cares about âeffectivenessâ because couples sometimes have âseriousâ or âgraveâ reasons to postpone pregnancy. My wife and I have that kind of reason. A couple must be able to trust the method they are using will be effective for them.
God gave us these fertility signs for our use. He knows that we need to be both Generous in receiving new life, and Prudent with the lives He has entrusted to us. That is the balance that NFP is used as a tool to decide. Yet any method is only a collection of information that we can use to modify our behavior. We are all dependent upon the Mercy of God to discern whether to postpone or achieve a pregnancy, and quibbling about different methods can often lead to a hardness of heart that serves the Enemy more than God.
I truly believe God has given us different NFP methods to serve different needs in the Body of Christ. I have my preferences, since I teach for CCL, but that is not a prejudice. Other methods are just as passionate about their methodology, as they should be, but that doesnât mean there is any conflict.
We had a student once who had used Depo Provera for seven years before she took our class. She promoted for our organization, but grew so frustrated with the damage done to her fertility by Depo, that she wanted to become part of the solution. She was a Nurse Practioner by training, and is now a Creighton Model NFP teacher. We celebrate her chioce to be an instrument of the Holy Spirit and take up the cause! Because she choose to teach another method is not a rejection of STM to us, itâs just a greater flowering of the Gifts of the Holy Spirit in the service of the Church.