Yes, and not just him but every prophet from the LDS for a number of important reasons
1. They've claimed that salvation is by faith and works when the Bible states that only faith alone saves (Ephesians 2:8-9).
2. They believed in the doctrine called Eternal Progression which states that the Godhead (the Father, the Son, and the Holy Spirit) was once men, and what they are nw, we can become (Isaiah 43:10).
3. That the Bible is inspired and inerrant "as far as it can be understood correctly"'. which really means, that the scriptures both old and new testament is not unless it agrees with the LDS prophets (Romans 15:4, 2 Timothy 3:16-17, & 1 Peter 3:20-21).
There are more false teachings by these men but these are among the most serious.
8 But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.
- Galatians 1:8
