Creeds are interesting in that they serve several functions in the Christian tradition. For many they are seen as a litmus test for who is Christian and who is not. I would submit that this is a misuse of the creeds of our tradition and to distill their role as just a test we all sign off on cheapens the richness of the creeds.
So what else are creeds?
I would submit that reciting the creed in corporate worship is more an act of humility and justice rather than a way to decide who is in and who is out. The creeds stated in worship, for the most part, are older than the people speaking them today. And this highlights why recited creeds are an act of humility and justice. Because these words are not "our" words means that we must stop talking and speak the words of others. When we speak these words we are humbled with the reality that others might have something to teach us.
Even more than that, when we give voice to the voiceless we participate in a act of justice. While the creeds are often written by those in power in their time, those people are no longer in power. Said another way, when we give voice to the powerless we recall all those who are powerless and voiceless.
So when you say a creed, perhaps you do not believe all (or any) of the lines, that is okay. Say them anyway. Say them as a practice of humility and as an act of justice. Then go out into the world and continue works of humility so that justice may be made real for all.
And perhaps, that is the greater goal of our creeds.