The Pharisee's were seeking the One True God. Incorrectly perhaps, but seeking, nevertheless.
I am sorry, but the Bible disagrees with your assertion above. Did not Jesus state, "seek, and
ye shall find" (Matthew 7:7), if the Pharisees were seeking God according to Jesus they would find (the verse says "shall" not "might), but rather the Pharisees crucified Christ! John 5:39 says, "Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me." Apparently, people like the Pharisees can perform religious acts such as attending service and even reading the scriptures, but not be seeking Jesus! If they were seeking Jesus, why did he call them Vipers?
Consider these verses,"23 Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone.24 Ye blind guides, which strain at a gnat, and swallow a camel.25 Woe unto you, scribes and Pharisees, hypocrites! for ye make clean the outside of the cup and of the platter, but within they are full of extortion and excess." (Matthew 23:23-25) and "33
Ye serpents, ye generation of vipers, how can ye escape the damnation of hell" (Matthew 23:33) Notice the Pharisees attended service, read scripture, and even paid tithe, however they were a generation of vipers who could not "escape the damnation of hell". Indeed they were very religious, but to assert they were "seeking" Jesus in light of the passages I just gave you is ridiculous, don't you think?