So I am a missionary in Liberia and some of the people here say we cannot see spirits yet there are multiple accounts of people seeing spirits like Moses and Jesus Christ and Wilford Woodruff and the founding Fathers. I just want to get some clarity on the subject.
The Lord bless you in your service to him as a missionary, and thank you for asking us this question. As Latter-day Saints we exercise faith in the following will, mind, and voice of the Lord: The Bible, Book of Mormon, Doctrine and Covenants, Pearl of Great Price, and modern day revelation from servants of our Lord Jesus Christ. In light of this, there are plenty of examples from our scriptures where “spirits” have been seen by people.
1) The Brother of Jared when asking the Lord to touch the rocks, he saw the finger of the Lord and then the whole spirit body of our Lord. This would be the greatest example and evidence from scripture that spirits can indeed be seen.
2) The angel Gabriel would have been a spirit of the just visiting Mary letting her know that she will carry and conceive the Savior of the world.
3) The experiences you have also mentioned in your initial question.
As to the knowledge we have received through past and modern revelation we know that spirits can indeed be seen in our lives, and that we can personally experience such events also. The only thing you can do in these circumstances is to provide the evidence from the authentic sources we have and then bear witness. Once you have born witness it is up to who you are speaking with to either accept or reject, which is out of your control as it is their moral agency.