When I was a youth pastor, I remember being contacted by one of the teens in our group about Christadelphians. They were nice people who believed in Jesus, was that not enough? Being not very familiar with them, I had to look into it. I have decided to revisit that. What is it that Christadelphians believe? You can find their full statement of faith here.
Instead of responding to every point, I will look at only two sections.
10. That being so begotten of God, and inhabited and used by God through the indwelling of the Holy Spirit, Jesus was Emmanuel, God with us, God manifested in the flesh-yet was, during his natural life, of like nature with mortal man, being made of a woman of the house and lineage of David, and therefore a sufferer, in the days of his flesh, from all the effects that came by Adam’s transgression including the death that passed upon all men, which he shared by partaking of their physical nature.
Christadelphians affirm Jesus as the Son of God, but only in that he was conceived in Mary by the Holy Spirit. Therefore Jesus was a human being who was conceived miraculously, filled with the Spirit, crucified, raised and will return. The problem is that this view does not deal with passages in John, Philippians, Colossians or Hebrews that clearly portray a pre-existent Son of God that was incarnated in Jesus of Nazareth.
16. That the way to obtain this salvation is to believe the Gospel they preached, and to take on the Name and service of Christ, by being thereupon immersed in water, and continuing patiently in the observance of all things he has commanded, none being recognized as his friends except those who do what he has commanded.
Historical Christianity teaches that salvation is by grace. We accept in faith that Jesus died for our sins and confess him as Lord. Christadelphians deny this, adding to faith both baptism and works. Of course our faith should be demonstrated by works, but it is not salvation by works. Paul is clear: “For it is by grace you have been saved, through faith—and this not from yourselves, it is the gift of God— not by works, so that no one can boast.” (Ephesians 2:8–9 NIV) I do not think that Paul could have been a Christadelphian.
I have no desire to insult Christadelphians. I am sure they are nice people who are sincere in their beliefs. However, their differences in the nature of Christ and the means of salvation mean that they should not be considered a part of historical Christianity.