The coin's inscription
This reads AVDV[ARL<ETH> RE]GES ('Of King Eadbald') on one side, and on the other IIPNNHWL IENVS (a corruption of '...nbal Londenus', for [Ea]nbald, London' which perhaps is an indication of the moneyer - the person who authorised the minting of the coin).
You can't always be sure of these inscriptions as they are often worn away with use and age.
Kent - a Christian region?
Eadbald's father, King Æthelberht, had recieved Saint Augustine and accepted Christianity but, after his death, Kent had at first reverted to paganism. The crosses on this coin show that Eadbald had accepted Christianity by the end of his reign.
Conversion involved a political as well as religious decision, and the designs on the coins would have been intended to impress Kent's neighbours as well as its own people. Eadbald was the first English king to be portrayed on a coin.
Revival of the coinage
In England, money had gone out of use at the end of the Roman period. During the 6th century, gold coins from the Continent arrived and began to circulate in England.
Soon after this, the Anglo-Saxons started making their own coins, like this one, partly for prestige reasons and partly for economic purposes - it was profitable to run a mint.
A rich man's coin
Gold coins were worth a lot because gold was even more valuable than it is now. This gold shilling would be equivalent to more than £100 today.
It wouldn't have been used for ordinary household transactions; for these they would have used barter or credit. The shillings were used for making gifts between rich people, buying land, paying fines or used by merchants in long distance trade.