Both the Sage of Six Paths and Sarutobi Hiruzen share the nickname "God Of Shinobi", and most people take this the complete wrong way, assuming that this is comparing Hiruzen to the Sage, as they fail to realize that there are different definitions for "God".
Rikudo Sennin was nicknamed God of Shinobi because he was the "almighty" of the Narutoverse. He could create anything he wanted, and he tamed the beast that was the juubi. He was a God under the definition of the creator/ruler of the Narutoverse.
Sarutobi Hiruzen was nicknamed God of Shinobi because he mastered the ninja arts. He was a master in nin, tai and genjutsu, and in his prime was incredibly strong, fast, durable and has always been extremely intelligent. He was nicknamed a God in the sense of being a powerful/respected person, or in other words, an idol. He was not considered a God in the same sense as the Rikudo Sennin.
Rikudo Sennin was nicknamed God of Shinobi because he was the "almighty" of the Narutoverse. He could create anything he wanted, and he tamed the beast that was the juubi. He was a God under the definition of the creator/ruler of the Narutoverse.
Sarutobi Hiruzen was nicknamed God of Shinobi because he mastered the ninja arts. He was a master in nin, tai and genjutsu, and in his prime was incredibly strong, fast, durable and has always been extremely intelligent. He was nicknamed a God in the sense of being a powerful/respected person, or in other words, an idol. He was not considered a God in the same sense as the Rikudo Sennin.