Sometimes we debate the 'top priority' in liturgy. Preaching > worship. No, worship > preaching. Says a third, No, mission > worship > preaching. So on. There is in fact a scriptural case for deeming nothing to be prioritised over another but to hold all such things as priority. The case goes like this (all revealed to me by that great means of learning something, teaching that something ... and this past semester I have been teaching Old Testament at Bishopdale Theological College, Nelson)!
Through the sweep of the Old Testament two great theologies jostle for attention. One is (so called) Deuteronomism which begins with Deuteronomy and its great thesis that Israel will be blessed if it keeps the Law given through Moses and will be cursed if it disobeys the Law; and then tells the history of Israel through Joshua, Judges, Ruth, 1 and 2 Samuel, and 1 and 2 Kings in the light of that thesis. The great triumph of Deuteronomism is to explain the shattering event of the exiles of northern Israel and then of southern Judah: disobedient (northern and southern) Israel has been punished.
The other could be called Zionism but to avoid confusion with modern Zionism, we will call it Templeism. Its primary texts are 1 and 2 Chronicles where the history of the world, and of Israel, beginning with Adam, is told in such a way as to make King David the central figure in Israel as the founder of Temple worship, and attitudes to the Temple and its worship the test of fidelity to Yahweh. Infidelity to Temple worship rather than to the Sinaitic covenant is the reason for exile; and the restoration of Temple worship is the great aim of return from exile.
Although 1 and 2 Chronicles in many places are word for word the same as passages from 1 and 2 Samuel and 1 and 2 Kings, the differences between the two accounts are striking. The Chronicler, for example, suppresses reference to David's decline through adultery, and subsequent failure to control his sons; to Solomon's foreign harem through whom came much worship of foreign gods; and to most of the prophetic activity through which Israel's disobedience to the Law is challenged. Striking also is an addition which the Chronicler makes to Israel's history when he tells us something omitted from 2 Kings: Mannasseh, one of the worst of the bad kings, repents, returns to Jerusalem and restores pure worship in the Temple (2 C 33; cf. 2 K 21).
These two theologies appear to promote what in today's church could be characterised as 'preaching'/'Scripture' and 'worship'/'liturgy'. The Deuteronomist seems convinced that the 'most important thing' is preaching the Word of God and urging obedience to it. The Chronicler argues differently. Vital to Israel is the worship of God by means of properly ordered liturgy. Which is correct?
Well, it is interesting that the wise ones of ancient Israel working on what was to be included in Israel's canonical Scripture determined that both theologies should be included, and made no comment about which was to be preferred. (Were they proto-Anglicans?)
The same Old Testament includes a glorious vision for the message of God being proclaimed to all nations. So there we have it. No need to debate priorities re worship, preaching, and mission. According to the Old Testament itself, all are equally important!