Shared with a coworker friend, in response to his sincere inquiry about how to know if the LDS Church is true, and what it requires to be a member:
You must believe that the LDS Church truly is led by Jesus Christ through His living Prophet and our 12 modern day Apostles, as well as be able to make a baptismal covenant that you will live by the standards of the Church before you can be baptized.
There is an interview process for all of that, and, of course, any prospective member may lie, but that's an issue between you and God, which takes care of itself.
Probably, for you, I would guess that using tobacco would be one of your greatest practical stumbling blocks.
For me, it was alcohol. (I was an alcoholic when I joined, and probably still am, even though I haven't had a drink since 1969)
Do members sometimes or even often struggle with issues of doctrine, practice, and especially our own personal behavior?
Of course we do, and we also are taught to pray earnestly and to search out all truth for ourselves, so that we know for ourselves and just are not merely led.
For me, my first step was to find out whether or not I believed Joseph Smith was a Prophet, and that the Church still is led by a living Prophet.
Reading and praying about the Book of Mormon (and also the Holy Bible, which is part of LDS Scripture) was a big step in convincing me of that, and led me to finally ask God if this all was true and if I should and could make changes in my life and be baptized.
The answer was not what I wanted to hear, but I never once doubted that the best decision I ever made in my life was to be baptized and join the Church.
It was hard.
It still is.
With that assurance, I was able to commit myself to baptism, and all my other questions and concerns became much easier when applied against those already answered questions and standards of eternal truth.
That doesn't mean Church leaders don't make mistakes, because they also are mortal, just like us, but God truly is at the helm of the LDS Church.
I that, I am absolutely convinced.
There is no doubt in my mind at all about that.
Repentance is a lifetime process for all of us, but the Grace of Jesus Christ is real.
All we have to do is make an honest effort, and He'll take care of all the rest.
Personally, I'm a recluse, and really don't much like going to Church or attending meetings, but I go because I know that God wants me there, because it's good for me and strengthens me.
I always feel the difference afterwards, too.
What helps me most is constant questioning conversation (prayer) with God and daily study of the Scriptures, even if only for 15 minutes each day.
We can talk some more, but you're the only one who can get an answer for yourself.
Don't give up, just keep praying and searching.
God knows your heart, and he will lead you to the truth you seek and need.