If your concept of testimony is blindly following any religious idea without scrutiny or inference, then everyone would be correct. Including Christians, Jews, Atheist, etc. Belief is based on logic, otherwise what is the point of dozens of verses describing nature? Faith in this context would be firm belief and knowledge in the existence of God.
On the other hand, Atheists seem to have trouble application using logic to infer the existence of things he didn't see when it comes to God, despite its constant use in daily life. For instance I reject the bible since it is written by unknown men at unknown places at unknown times, and edited by unknown men at unknown places at unknown times, along with Christianity embracing inherently contradictory concepts such as the Trinity (Jesus is God, Holy Ghost is God, God has three persons, The father doesn't have three persons, the Holy Ghost is not Jesus, ugh.. you get the idea).
I believe in what is possible, on the other hand Atheists believe on what is impossible, because Atheist faith absolutely collapses logic and self-evident truths; might as well say 1 + 1 doesn't equal 2 since objectivity of logic, existence of free will, and existence of morality is denied.
We also have scenarios of the evolution of sexual pairs, in which you need to deny the existence of purpose in every detail starting with sperm, egg, fertilization, movement, nutrition, womb, to a birth. We have claims that milk evolved from licking sweat. We have amusing make-believe stories about useless wings evolution gradually through comical and fictitious mechanisms. We have racoon being ancestors to blue whales. We have poor people actually deluding themselves into believing DNA and life are simple stuff. There are countless impossible scenarios and dilemmas that are an absolute laughing stock.
I reject the existence of your great grandmother since there is no empirical evidence of her existence.
To sum it up:
I have valid reasons to support what I believe (authentic testimony being sufficient).
You don't have valid reasons to reject what I believe (and if you do it is question-begging for me).
You should make logical objections such as questioning the soundness or validity of my position.