Which one sounds better in a contemp christian band? i wanna play a Tenor, but i hear that altos and sopranos sound better in a contemp band... wanna help me out?

I would definitely think Tenor would sound better. Then alto, then soprano.

Just because the tone of the Tenor better blends with other instruments. But then, it all depends on what other instruments are in the band too ??

And, IMHO, I think people enjoy the more soothing (?) sound of tenor more than alto and definitely more than soprano. YMMV

You may want to also ask the director of the band too. I`m sure he may, or may not, have a preference.