Yaakov wakes up from his dream of the laddr and Hashem speaking to him and declares in 28:20-21, "If Hashem will be with me and guard me on the way that I am going and give me bread to eat and clothes to wear and if I will get home to my family safely, then hashem will be to me for my God and I will..."
This is our forefather Yaakov? The "איש תם יושב אהלים"? This is the same Yaakov who just had a dream in which Hashem spoke to him and he woke up and said he only now realized how holy the place was, etc..? he is making his acceptance of Hashem conditional on Hashem giving him bread and clothes? Wasn't Hashem already his God?
And how is this different than what many of us do? We "test" Hashem and say if I pass this test I will keep shabbos, or if I win the lottery I will do x y or z, etc. Was Yaakov doing the same "test of Hashem" and is that what his faith was based on?