The name Strength From Within in Chinese / Japanese...

堅忍 means persistent, steadfast, fortitude, and/or perseverance.

The first character means strong, solid, firm, unyielding, or resolute.
The second character means to beat, endure, or tolerate.
Together they speak of the strength from within yourself. Some may also translate this as long-suffering in a more Biblical sense.

堅忍 is a common term in Chinese and Korean Hanja but a little less commonly used in modern Japanese Kanji. For that reason, this selection is best if your audience is Chinese or Korean.

Note that when writing this as Kanji, Japanese will tend to write the second Kanji a little differently. If you select our Japanese master calligrapher, please expect the form where the little horizontal stroke crosses the vertical stroke. See differences in the images to the right. Technically, they are both the same character, and will be read the same in either language.

表壯不如里壯 literally translates as: [Better to be] strong inside than [to be] strong outside.

The ancient original meaning was:
[An] able [husband] outside [working to support a family is] not as good as [an] able [wife] inside [working and saving to take care of the family].

The current meaning is:
Inner strength is more important than outward appearance.

内面の強さは外見の良さに勝る is a Japanese proverb that literally translates as “inner/internal strength/power [versus] outward-appearance [the] merit/virtue/good quality [does] excel/surpass/exceed/outweigh.”

More naturally in English, this would be “Inner Strength Outweighs Outward Appearance.”

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.

內在力量 is the slightly-verbose way to say inner strength.

The first two characters mean “intrinsic” or “inner.” The second two characters mean “power,” “force” or “strength” (especially physical strength). 內在力量 is more a short phrase rather than just a word in Chinese and Korean. This can sort of be understood in Japanese but it's not normal/proper Japanese.

內力 is the shorter version of inner strength (can also be translated as “internal force”). The first character holds the meaning of “inner” or “internal.” The second character means “power,” “force,” or “strength.”

內力 is a Kung Fu way of talking about an inner power or strength from within. This is a way to express “inner chi.” This is something that you might hear in a real Chinese Kung Fu movie.

While understood in Chinese and Japanese, this can have a secondary meaning of “inner stress” in Japanese.

自強 is the kind of inner strength that applies to a person who has will-power and can inspire themselves to do great things.

自強 can also be the creed of a person that always pursues self-improvement.

Other translations: self-strengthening, striving for improvement, self-improvement, striving to become stronger, and self-renewal.

力愛不二 is a proverb that literally means:
“Strength [and] Love [are] Not Two [separate ideas/concepts/things].”

You'll find this proverb translated from Japanese to English as:
Love and strength are not separate.
Power and love are indivisible.
Strength and love in harmony.
Strength and love stand together.

Old Japanese grammar is quite different than English, and so this proverb says a lot within the brevity of just 4 characters. If you just read these characters directly as “Strength Love Not Two,” you'd probably miss the real meaning.

According to the Swedish Shorinji Kempo Federation, this is the second characteristic of Shorinji Kempo.

This post really explains the concept best in my opinion: Bushido by MS: Riki Ai Fu Ni, which states: "Riki Ai Funi" is the philosophy that power (Riki) and love (Ai) are indivisible. More concretely, a person, who is powerful but does not have love, cannot control and misuse his/her power; on the other hand, a person, who has loved ones but is not powerful enough, cannot protect himself/herself nor loved ones.

自強不息 is a proverb or idiom that suggests that the pursuit of self-improvement is eternal. It can also be a suggestion to strive unremittingly in life.

The first two characters mean inner strength with the idea of self-improvement. The last two characters mean “never rest” or “striving without giving up.”

Some will translate these four characters as “Exert and strive hard without any let-up.”