Not surprisingly the word 'God' is very common in English Bibles occurring 4,470 times in a total of 3,863 verses. It is also used to render a large number of words; twelve in the Old Testament and twelve in the New. However not all of these renderings reflect a divine characterization within the original language; they reflect an idiomatic usage of the term 'God' in Elizabethan English designed to suggest the extremity of an imprecation. In fact there are seventeen occasions when the term 'God' is used without any underlying word in the original at all. In the following I will comment briefly upon these more stylistic uses of the term God before digging into the more direct translations in greater depth.
In terms of the number of underlying words translated the largest single group of idiomatic usages stems from the phrase 'Would God' or 'Would to God'; it is a rendering of three different Hebrew words and one Greek. The first encountered is the pair mîy (H4310) nâthan(H5414) which literally means 'who gives?' and appears to be similar in meaning to the American 'what gives?' It is also rendered 'O That'. H3863 (lû) is a conditional particle often rendered 'O that' or 'if only' that is rendered 'Would God' on three occasions. The last of the Hebrew words rendered 'would God' is 'achălêy(H305) occurring twice only; once invoking the divine title. This is an interjection that could reasonably be rendered 'O that!' The Greek word rendered 'Would to God' is ophelon (G3785) and is a particle expressing a desire that things had or would turn out differently.
The Hebrew word châlilâh(H2486) literally means a profaned thing and is used interjectionally to mean 'far be it'. On nine occasions the divine imprecation against profanity is highlighted by rendering the word as 'God forbid'. The Greek word-pair rendered God Forbid has no such link. Ginomai mē (G1096 G3361) literally means 'be not' or 'become not'; the fifteen occasions it is rendered 'God Forbid' are essentially translational license. It should be noted that most of those renderings (10) occur in Romans.
Another idiomatic use of the word 'God' appears eight times between 1Sa and 2 Chr where the expression 'God Save' is used as a rendering of châyâh. Châyâh is a relatively common Old Testament word generally meaning to live, have life or to live prosperously. It is rendered 'live' (110), lived(39), alive(34), save(21), quicken(12) and others. It is rendered 'God Save' when used of a king; thus 'God Save the King'.
A somewhat more intriguing use of God is as a rendering of bêytḣ'êl. This Hebrew word literally means 'house of God' although generally it is simply transliterated to 'Bethel' to refer to the Palestinian city of that name. However on five occasions; four in Judges 20-21 and once in Zec 7:2 the meaning of the word is expanded out and implies the temple (or tabernacle in the case of Judges). The new translations (NET, NASB) use the town-name in these places; the NKJV keeps the authorized rendering but with a marginal note.
The New Testament invokes the divine name directly, explicitly, implicitly and idiomatically! An example of an implicit use is the word chrēmatizō (G5537). It can be used of a business transaction or public pronouncement but it can also refer to the response from an oracle. Thus we can understand that of the nine times the word occurs it is rendered 'warned of God' on four of them. It is also rendered as 'revealed by the Holy Spirit' and 'admonished of God'. The other three occurrences are secular. The noun form (G5538) occurs once where it is rendered 'answer of God'.
An explicit use of God comes from the decomposition of the singularly occurring Greek word theomacheō (G2313). The components of the word are theos (God) and machomai (G3164) 'to fight' thus the word is rendered 'fight against God'. A similar decompositional approach gives us 'Hater of God' from theostugēs(G2319) in Rom1:30, 'lovers of God' from philotheos (G5377) in 2Ti 3:4 and 'without God' from atheos (G112) in Eph 2:12.
An idiomatic use of God occurs in the expression 'God Speed' occurring in 2Jn 1:10,11. It is a rendering of chairō (G5463) which means to rejoice or thrive and which can be used as a salutation. It is most commonly rendered rejoice(39), glad(14) or hail(6).
The remaining words that are rendered as 'God' are all rather more direct invocations of deity. There are six of these in the Hebrew and two in the Greek.
The first of these encountered is 'ĕlôhîym (H430). The word is plural and literally means 'gods' although it is usually used, especially with the article, to mean the supreme God. Of the 2605 times the word occurs it is rendered 'God' on 2366 of them; 'gods' on 223 with just a handful of other renderings. 'ĕlôhîym is the intensive plural of the singular form 'ĕlôahh (H433) which is much rarer occurring only 56 times and is always rendered 'god' although it can refer to the true God or a false one. The Aramaic of 'ĕlôahh is 'ĕlâhh (H426) which is rendered as 'God' on 95 occasions within Ezra and Daniel.
'ĕlôahh is in turn emphatically derived from 'êl (H410) which is another Hebrew word rendered God (224 times). When not rendered as God it is translated mighty(6), power(3), goodly, great, mighty or strong (all once). Brown, Driver and Briggs literally render 'êl as 'mighty' or 'strength'. We thus see that in the 'el' family the most commonest form starts with the concept of might ('êl) adds emphasis ('ĕlôahh) adds intensity and ends up with the most first Biblical name for God that we have!
The commonest and perhaps most famous name for God is yehôvâh(H3068). However, it is only actually rendered as 'God' in our Bibles on four occasions. By far the more common translation is 'Lord' (6,412 occasions). It literally means 'the existing one' and is described by BDB as the one true name of deity. There is another variant of it 'yehôvih' (H3069) which is usually used in the expression 'Lord God'. It is rendered as 'God' on every occasion it appears.
The Greek derivation of the word God is rather simpler. The general appellation of deity is theos (G2316). The word is rendered God 1310 times otherwise god's(16), gods (8), godly(7), god-ward(2). Whilst accurate the word is much less personal than the Hebrew; it can be used of anyone considered to be a God independent of character.
An orthogonal word rendered as God is kurios (G2962). The word is a noun which means 'supreme'. It refers to one who possesses or who is able to dispose of a matter. In some senses it is similar to the 'might' of 'el except that it relates to the positional ability to do something and does not necessarily imply an integral ability. Much like Jehovah it is usually translated as Lord (703) being rendered as 'God' only once (Acts 19:20).
We therefore see that if we principally measure according to the numbers of the occasions when the word 'God' actually occurs in the Bible it will be a translation of one of two words. In the Old Testament it will be 'ĕlôhîym an intensive form of an emphatic derivation of might. In the New it will be a simpler, crisper but somewhat less evocative 'Deity' However we also should take away that for such a fundamental word it has been used rather freely and it is worth looking in some form of reference to see what was really said on the occasions it is used.