In my studies yesterday I came across this scripture which seems applicable to discussions I’ve had with anti-Mormons, as well as honest truth-seekers. These are the words of Lehi as he speaks to his rebellious sons Laman and Lemuel:
For he truly spake many great things unto them, which were hard to be understood, save a man should inquire of the Lord; and they being hard in their hearts, therefore they did not look unto the Lord as they ought.
Sometimes we might feel we are speaking “many great things” to someone regarding the gospel, but I’ve found that no amount of words is convincing in and of themselves. One may speak all day long to someone of the gospel and it will have no effect until the recipient looks unto the Lord and is open to the Spirit. Thus while it is important to make sure people receive the word of God and have a chance to ponder the word, ultimately our intellectual capacities are not capable of knowing whether the words are true or not. Up until the moment proof is received it is all theory. It might sound nice, but it’s still theory. Only when someone receives the witness of the Spirit, proof that the gospel is true, does theory become fact for that individual.