To quote "The Art of Peace" by O'Sensei (translated by John Stevens)
"The Art of Peace (aikido) that I practice has room for each of the world's eight million gods, and I cooperate with them all. The God of Peace is very great and enjoins all that is divine and enlightened in every land."
As others have said already.
I think you must make up your own mind about the compatibility of Aikido and your religion (Christianity).
If you find yourselve at odds or uncomfortable with it...in the long term you are doing yourself harm from both an aikido perspective and a religious perspective.
I don't think honestly that anyone here in this forum can validate or legitimitize your own beliefs on religion/aikido.
For me, aikido is both a spiritual path, and a religous practice since it teaches me and reminds me that I am but a part of the big machine and in order to succeed and be happy, I need to be aware of my surroundings and be at peace with things and people in the world.
Frankly, I find that to be the same goals of ANY religion and perfectly compatible with the fundamentals of Christanity.
Aikido is non-dogmatic, and is therefore should cause you no conflicts...but then again, that is a choice you must make on your own!
good luck in your path to happiness and fulfillment!