A surprising fact is that there is in reality an unbelievably wild variety of different kinds of gods that exist among the followers of a monotheist religion like Christianity. The situation is caused by the simple fact that every believer does create a personal version of the original idea of god in his or her mind. This personal idea will fit his or her personal needs and requirements.
This is normally the case even if that person would personally believe that he is sharing a quite common garden variety of god with his or her co-religionists. A human mind just works so that it picks and chooses things from a complicated thing like a religion according to his or her own preferences. This normally happens without the person in question even realizing it.

A modern, rational Christian may pick and choose only the rationally acceptable bits and parts from his or her religion. He or she may eventually see his or her personal version of religion and its god as a quite rational construction.
However, the core problem is that even the gods of the modern organized religions are strongly rooted in irrational claims. In fact, the very essence of faith is to believe in something unbelievable, as only this act of believing in itself makes you a true believer.

Have you noticed that in the core of every single one of the successful religions there are some irrational claims that are very hard to believe? Believe me; they are there for a purpose. Without the leap of faith there could not be such true bond of faith that all really successful religions need from their core adherents.
When this core group is assembled and high enough social status for the religion is achieved by their work the great indifferent mass will follow by force of tradition and social pressure.

 Detail of Sistine Chapel fresco Creation of the Sun and Moon by Michelangelo (c. 1512), a well known example of the depiction of God the Father in Western art.- Wikipedia

Religions which do not include any kind of "leap of faith" have already become quite extinct. "Leap of faith" just happens to be the only known way to create the kind of extremely lasting mental glue that can really bind followers to a religion.
The very hard mental exercise that is needed to accept the unbelievable claims of a religion is also an investment people do not want to go waste. They are often willing also to protect this investment that they have already made. This willingness is an important tool in the process of creating long-lasting religions.

So, if you sincerely believe in any of the gods any of the major current world religions, you are out in the cold in the field of rationality. Your faith just must be irrational to be faith at all.
The Einsteinian pantheistic entity that is also called "god" is very different thing altogether. In fact, this deistic creature has nothing to do with the gods of the modern world religions at all. In fact, it is just a way to describe the workings of the universe.

(This piece was completely refurbished on 30th of September, 2012)