strong: possessing real, built-in force that grips, holds, and resists
This word points to strength a person or thing actually has and can put to use, not merely a capacity or a rank. It is the sturdiness of a healthy body, the might of a soldier, the pull of a gale, the roar of a shout. The same word covers all of these because they share one idea: force that is really present and hard to overcome.
Because the strength is real and measurable, the New Testament writers reach for this word again and again in scenes where one power is set against another and readers are meant to ask which will win. The powerful of the earth hide from wrath they cannot resist. A well-armed man guards his house until someone tougher arrives. God's apparent weakness turns out to overpower every human measure of might.
One feature sets this word apart from its close relatives: it can describe forces that are not people at all. A famine, a cry, a voice, a wind, even a letter can be called strong, meaning severe, loud, or forceful. That flexibility, applying the same core idea to persons and to impersonal forces alike, is what makes it hard to pin to a single English word.