[Salvation]

No birth control is used. It’s being aware of a woman’s fertility cycle.

And like you said, God steps in sometimes and couples have a surprise, which they readily accept.

No problem.

[blackpacific]

As Humanae Vitae wisely puts it, “every marriage act must be open to new life”. The Holy Spirit has spoken. NFP falls within this guideline.

[UnRuley1]

Are you so sure the "readily accept" the surprises God gives them? Do you know the statistics of the number of catholic women who seek abortions? It is significant. All I am pointing out here, is the very terminology being used is "family planning" which we all know is code for contraception and abortion. Once you accustom people to this way of thinking it isn't a far leap to go from Natural "family planning" to abortion. And many do make that leap in order to "plan" their families. In my mind, when ever I see or here the term "family planning" I automatically think "abortion".
The communists and Nazis understood how control of the language was effective in controlling the people. I believe the church was duped into accepting the anti-life terminology precisely to set up the contraceptive/abortion mentality thereby ensuring that we catholics would not grow the church.