Understanding the Significance of Diatereo in Greek

διατηρέω means “to keep,” and it appears in two New Testament scenes: Mary’s inward response to events surrounding Jesus’ youth, and the practical instructions sent to Gentile believers by the Jerusalem leaders.

Root and Related Words

διατηρέω is formed from dia (διά), “through/because of,” and tereo (τηρέω), “to keep: observe.” The combination places the action of keeping in a way that is connected with dia’s sense of movement or causation (“through/because of”) and tereo’s basic idea of keeping/observing.

Occurrences

Luke 2:51: “And he went down with them, and came to Nazareth. He was subject to them, and his mother kept all these sayings in her heart.”

Here διατηρέω describes Mary’s response to “all these sayings.” The verse sets a calm, domestic scene after movement (“went down… came to Nazareth”) and after the statement about Jesus’ posture within the family (“He was subject to them”). Against that outward order—travel completed, life resumed, a son living under parental authority—the verb turns attention inward: Mary “kept” a body of remembered words. The object is not a single phrase but a collected set (“all these sayings”), and the location is explicitly personal and internal (“in her heart”). In this context, keeping is not guarding a physical item but holding words so they remain present within her. The verse portrays memory and reflection as an active, purposeful keeping, where sayings are preserved rather than allowed to dissipate.

The surrounding details in the sentence also shape how the keeping is heard. The narrative moves from external actions (going down, coming) to a relational description (being subject) and then to Mary’s internal act. διατηρέω functions as the verb that gathers up what has happened and what has been spoken into an ongoing inner register. By placing the keeping “in her heart,” the line presents keeping as something that takes place at the center of her inner life: she retains and holds the sayings as something worth carrying forward.

Acts 15:29: “that you abstain from things sacrificed to idols, from blood, from things strangled, and from sexual immorality, from which if you keep yourselves, it will be well with you. Farewell.”

In Acts 15:29, διατηρέω appears in a different setting: a formal set of instructions, expressed as a list. The recipients are told “that you abstain” from several items, and then the verse adds a conditional reassurance: “from which if you keep yourselves, it will be well with you.” Here the verb is applied reflexively (“keep yourselves”), and the keeping is tied to the preceding abstentions. The clause “from which” points back to the list, so the keeping is expressed as self-maintenance in relation to those practices: the readers are to maintain themselves in a state characterized by abstaining from them.

The outcome is also specified: “it will be well with you.” The verb thus carries practical weight. It is not merely about retaining information but about sustaining a course of life aligned with the instruction just given. In this letter-like setting, keeping is presented as an ongoing responsibility that affects communal well-being and harmony—something that can be maintained over time, not a one-time reaction. The closing “Farewell.” frames the instruction as a complete message: the keeping is what remains with the hearers after the messengers’ words end.

Sense and Usage

Across these two passages, διατηρέω (“to keep”) operates in two complementary domains: an inward keeping of words and a lived keeping of oneself in relation to guidance. In Luke 2:51, what is kept is “sayings,” and the keeping happens “in her heart.” The act is quiet, private, and receptive: words are retained and held within the person. Keeping, in that setting, protects the sayings from being lost to time or distraction and presents an ongoing attentiveness to what has been spoken.

In Acts 15:29, what is kept is not a set of sayings but “yourselves,” and the keeping is defined by separation from the listed practices (“from which”). The focus shifts from storing words internally to sustaining a way of life externally, though still with personal agency: the readers are responsible for their own keeping. The conditional form (“if you keep yourselves”) expresses keeping as perseverance—an action that must continue in order for the stated benefit (“it will be well with you”) to be realized.

These uses show how “to keep” can describe both preservation and maintenance. The Luke scene presents keeping as holding something received—sayings collected and treasured within. The Acts scene presents keeping as guarding one’s conduct—maintaining oneself at a distance from specified behaviors. In both cases, the verb implies continuity: Mary’s keeping is not a momentary notice but an ongoing inward holding; the believers’ keeping is not a single decision but sustained self-keeping. The verb thus serves as a bridge between what is heard and what is lived: words can be kept in the heart, and persons can be kept in a pattern of abstention.

Imagery

The imagery suggested by these verses is simple and concrete. In Luke 2:51, the scene is a mother carrying “sayings” within her—an inner storehouse where words remain safe and present. In Acts 15:29, the picture is of a person keeping themselves clear of certain things, as one would keep oneself apart from what would compromise well-being. Together these passages portray keeping as both holding close and holding back: preserving what is worth retaining and maintaining distance from what must be avoided.

Sources: Lexical data from Strong’s Exhaustive Concordance and the Translators Brief Lexicon of Extended Strongs for Greek (STEPBible, CC BY). Occurrence data from the Translators Amalgamated Greek New Testament (STEPBible, CC BY). Scripture quotations from the World English Bible (public domain).