Not many people know that the Nicene Creed was not understood by all in the same way when it was first written. The few who do know this, usually twist this fact into a horribly misrepresentative attack on the Catholic Church. The ones who had the worst interpretation of it centuries ago were the Arians; and they were the ones it largely was written to refute!
After a lot of quarreling, and debating, and quarreling, and some more quarreling, the Church clarified the meaning of the Nicene Creed at the Council of Toledo around A.D. 598, by adding in the "filioque" wording. This made it clear what was being said, so it could not be twisted any more. Yet, notice the date; the Council of Toledo was over a century after the Nicene Creed was written! That is not "later ideas", but rather the Church being patient with making changes.
Yet, imagine being alive in the midst of that time before the clarification was made. It would be kind of like living right now. Right now: after the Second Vatican Council was closed, but before an authoritative doctrinal clarification of what was said and what was meant. It will likely happen some day (it needs to happen or we will struggle with divergent opinions forever), but we have not yet arrived there. There are radically different opinions of what "Vatican 2" means, and we have to trust that our Lord Jesus will clear things up for the Church eventually. We might not live to see it, but Christ always leads us into His truth eventually.