there were certain problems with the nicene creed. in 529, the so-called filioque clause was added to the creed. this clause is one of the main differences between the roman catholic church and the eastern orthodox church. the catholic church has this clause, the eastern orthodox church does not. the clause is about how godly the father is, compared to the son. where the original nicene creed reads "we believe in the holy spirit ... who proceeds from the father", the altered, roman catholic version reads "we believe in the holy spirit ... who proceeds from the father "and the son"". roman catholic christians accept this change, but eastern orthodox christians reject it. many eastern catholic churches (eastern in liturgy but in full communion with the pope) do not use the clause in their creed. they do think the doctrine it represents is true, though, as this is a dogma of the roman catholic faith. many protestant churches who take a position in this matter, usually accept the "filioque".