福 = Good Fortune, Blessed.
Why does this word means Good Fortune, Blessed?
Just for general interest, look at the word, (pronounced as fú,), carefully and you will see:-
--- on the left the radical 礻, (pronounced as "shì", originally written as "示") which denotes things of a spiritual nature, deities, etc, and thus by metaphorical association, things of an auspicious, spiritually positive nature. And as the Chinese practice ancestor worship, it therefore denotes the blessings bestowed by the ancestors who are present in spirit among the living. Thus the word for deity, god, 神 also has this radical.
--- on top is the word "一", meaning "one", "yī", (but pronounced as “héng" when used as a radical).
--- below this "一" are the words:-
--- "口", (pronounced "kǒu"), meaning "mouth", or "having food to eat“, and,
--- "田”, (pronounced "tián"), meaning "field" or "landed property",which in ancient times, actually even now, the opportunity to plant crops, principally rice, wheat, and thus long term sustainable survival.
So, put all the words and their putative meanings together, 礻, 一, 口, 田, you get the synergism:-
福, (Good Fortune, Blessed), which is the cumulative consequence of blessings from one's ancestors, god, as well as having landed property to plant crops and thus have food to eat.
As the Chinese would say 有一口饭吃, (Yǒu yī kǒu fàn chī), (have a mouthful of rice to eat), which in ancient China when starvation was an ever present threat it was truly good fortune and a blessing.