Many years ago I created a simple statement...
I wish everyone would be Mormons...
Knowing that I won't see that, I wish everyone would be Christians...
Knowing that I won't see that, I wish everyone would be good people...
Sadly, I won't see that, either.
There are many people who challenge the right of members of the Church of Jesus Christ of Latter-day Saints to participate on this Stack because they don't believe we are Christians. This is entirely true — from their perspective, we do not believe in the same Jesus Christ, we do not accept their beliefs or their salvation, we are not part of their theology. Therefore, from their perspective, we are not Christians.
Ecclesiastically, the feeling is mutual.
And he said unto me: Behold there are save two churches only; the one is the church of the Lamb of God, and the other is the church of the devil; wherefore, whoso belongeth not to the church of the Lamb of God belongeth to that great church, which is the mother of abominations; and she is the whore of all the earth. (1 Nephi 14:10)
So when you ask the question, do we believe that members of churches that deny the divinity of Jesus Christ are Christians, as you can see, the question is somewhat moot. We believe there are two churches: the Church of the Lamb of God, the vessel of Christ's authority on Earth, the administrator of His ordinances... and everyone else.
Christians vs. christians
We do not deny at all that there is good in many (indeed, most) churches. We do not deny at all that there are good people who are not members of the LDS Church. Indeed, we do not deny at all that there will be people who walk the Earth who will receive exaltation in the Celestial Kingdom who did not join the Church of the Lamb of God in this life. (And, if you corner us, we'll admit that there will be too many members of the LDS Church who will find themselves in the Telestial and Terrestrial kingdoms, but that's a story for another day. No church can force a person to heaven.)
But we do recognize and appreciate that there are people in the Earth who are living christian lives, even though they either have not been offered the opportunity to embrace the Church of the Lamb of God, or do not understand the import of the offer, or have chosen not to do so. We believe this is worrisome because we strive to love all people and seek their best eternal welfare. But we recognize that many will not see that what is offered is a pearl of great price.
Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven. Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? And then will I profess unto them, I never knew you: depart from me, ye that work iniquity. (Matt 7:22-24)
We also recognize that every other Christ-centered church on Earth will use that same verse against us. It was this very problem, the inability through the Bible to clearly identify which church was the true church of Jesus Christ that led Joseph Smith to pray and, through the blessing and marvel of God, change the world.
So, as you can see, your question is somewhat moot. Subdividing the various faiths into categories with the question, "do you consider them Christians?" doesn't make sense to us. Many will take upon themselves the name of Jesus Christ, and in so doing, are christians.
But few will embrace the fullness of the Gospel of Jesus Christ, few will apply themselves to His ordinances, performed with true authority (obviously from our perspective). Therefore, few will be Christians, meaning few have or will join the Church of the Lamb of God, the one true church compared to which all others, regardless their beliefs, are not.