M ex-fiance's father is a Baptist missionary.
To my face, he was charming, and we discussed topics such as Grace and Faith over the washing up, gardening, etc. We agreed, exchanged thoughts, and I found our discussions edifying.
When I was not in his direct company however, he mailed packages of leaflets to me: How to become a Christian, all those sorts of things. He wrote me letters about how he found God age 16, and how he had been a
sanctified soul ever since. (WHAT?

) He told me the only way for me to find peace in life would be to find God, just like he did, and that I could do this by stopping going to my ridiculous 'church' and by reading the leaflets he sent me and simply letting Christ in.
I felt angry, and I mentally composed letters to reply.
I then considered simply sending back the leaflets and his letter.
I then considered ordering him a rosary and some real theology to browse.
In the end I did nothing. He'd utterly destroyed the spiritual life of his son (my ex), and I decided that leaving him well alone was the best option. He'll be judged and corrected by someone far more important than me some day.