I want to know if Christadelphians can be considered Christians. They preach the gospel and baptize scripturally. Just that some of their unbeliefs are frightening. Are they Christians even if they are compromised on some things?
The Christadelphians trace their roots back to a British physician named John Thomas. He came to the United States and became a part of the churches of Christ in 1832. He worked as a traveling preacher for a while but gradually started teaching strange beliefs. This led to his disfellowship in 1837. He rebaptized himself and started his own group.
In 1843, Thomas ran into William Miller, the eventual founder of the Seventh-Day Adventists. He agreed with Miller's premillennialist views and admired Miller's willingness to question accepted beliefs. Thomas went to New York in 1846 and talk a series of lectures that became the foundation for his book Elpis Israel (The Hope of Israel). This book became the defining set of beliefs for his followers.
Initially, the group was called The Royal Association of Believers, but in 1864, John Thomas changed the name to Christadelphians (Brethren in Christ). They refuse to use the word "church" and instead refer to the group by the Greek word ecclesia.
There are no preachers in this group. Instead, male volunteers, called lecturing brethren, managing brethren, and presiding brethren, take turns conducting the assemblies.
What makes Christadelphians different from the church is their belief that souls are not immortal. The dead are unconscious until Christ's return. This conflicts with Jesus' teaching in Luke 16:19-31.
They believe that heaven will be on a restored earth and not in a spiritual realm (conflicting with II Peter 3:10-13). They claim that Jesus will reign over the earth from Jerusalem at his return. Hell does not exist. Some claim the wicked will be destroyed. The rest claim that the wicked will remain unconscious in death. Again, this conflicts with Jesus' teaching (John 5:28-20; Matthew 25:31-46).
Christadelphians do not believe that the Holy Spirit is a being and a part of the Godhead. They claim that the Spirit is only a driving force. Jesus did not pre-exist his incarnation on earth (conflicting with John 8:58). They deny that Jesus is God, saying that God cannot die (This conflicts with John 1:1).
They also deny that Satan is the source of evil. Instead, they say that God is the source of both good and evil (a conflict with James 1:13 and I John 1:5).
In answer to your question, can a person be considered a follower of Christ when they do not even believe who Christ is? "But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God" (John 1:12-14).
"I do not ask on behalf of these alone, but for those also who believe in Me through their word; that they may all be one; even as You, Father, are in Me and I in You, that they also may be in Us, so that the world may believe that You sent Me. The glory which You have given Me I have given to them, that they may be one, just as We are one; I in them and You in Me, that they may be perfected in unity, so that the world may know that You sent Me, and loved them, even as You have loved Me" (John 17:20-23).