Several parts combine into one character.

Compound character with three components: 爻 (teaching marks / divinatory knots) on top, 子 (child) in the middle, and 攵 (a hand wielding a stick — the strike-radical) on the right. The encoded scene is uncomfortable to modern eyes: a teacher striking a child while showing them how to read knot-marks. Ancient pedagogy was physical. Identical across 繁體 / 新字体 / 简体. Pairs with 学 / 學 (to learn) — together 教 + 学 = "teach + learn" form the foundational education pair.

The meaning extends from instruction to organized doctrine — religion as systematic teaching: 宗教 (religion), 仏教 (Buddhism — "teaching of Buddha"), 道教 (Daoism), 基督教 (Christianity — "teaching of Christ"), イスラム教 (Islam — "teaching of Islam"). In CJK languages, every world religion is named with 教 as the suffix.

Mandarin: jiào, falling 4th tone (verb / noun) and jiāo (verb only) — another 破音字: — jiào: educational system, religion, doctrine. 教育 (jiàoyù, education), 教师 (jiàoshī, teacher), 宗教 (zōngjiào, religion), 教室 (jiàoshì, classroom), 教科书 (jiàokēshū, textbook). — jiāo: the action of teaching. 教书 (jiāoshū, to teach books), 教汉语 (jiāo Hànyǔ, to teach Chinese), 教我 (jiāo wǒ, teach me). The tone shift between jiào (formal noun/system) and jiāo (everyday verb) is precise and important.

Japanese: on-reading キョウ (kyō) is dominant — 教育 (kyōiku, education), 教室 (kyōshitsu, classroom), 教師 (kyōshi, teacher), 宗教 (shūkyō, religion), 教会 (kyōkai, church), 教科書 (kyōkasho, textbook), 仏教 (Bukkyō, Buddhism), キリスト教 (Kirisutokyō, Christianity). Kun-reading おし.える (oshi.eru, to teach) is the everyday verb. Pairs with 学ぶ (manabu, to learn) and the foundational student-teacher relationship is encoded in this two-character pair.

Memory aid: an old teacher with a stick and a child — pedagogy from the bronze age, still embedded in the kanji.