Re: Is it a penis or....
one of the three gods mentioned in the first part of the Bible (Adonai, Elohim and Yahweh)
Yet another example of "a little knowledge is a dangerous thing"..
Adonai is an Aramaic word (the New Testament and bits of the OT were written in Aramaic - most of the OT was written in Ancient Hebrew) that is cognate with 'Lord'. The Ancient (and Modern) Jews have a proscription about using the names of God directly (YHWH being one of them) and so used the word 'Adonai' as a placeholder. Much the same way as we say 'Lord' instead of using YHWH.
Elohim (which is plural) simply means "mighty ones" (or "sons of God" - 'El' means God/mighty power in ancient Hebrew and is used sometimes and one of the Names of God). Sometimes used to refer to angels, other times used to refer to the faithful.
YHWH is a word that stands in for the phrase "I am what I am" (one of the names of God that declares his purpose - can also be stated as "I will be what I will be" - Ancient Hebrew only had two tenses - past complete and incomplete). Also note that ancient Hebrew had no written vowels so modern English has added in the extra vowels to give some idea of the pronunciation.
So in summary (and apologies for the Biblical nerdism), your reasoning and example are utterly wrong since none of the three names you mentioned are anything to do with an acient fertility god. There were gods who were referred to using 'El' - but only because all the langueages in the area were related and used similar names. Not three Gods, but different names for the same God (and one name that is plural and doesn't refer to God at all - as in the ancient sh'ma: "Hear O Israel, the Lord our God is One" - which in Modern Hebrew uses 'Adonai' as a placeholder.).
And yes, I have studied that stuff - for a lot of my life.