The last time worshippers prayed in the main sanctuary at Beth David Congregation, a forbidding wooden wall stood between them and their spiritual leaders.

Those called to the Torah had to climb 10 steps to the bima (pulpit), symbolizing the ascent to a place accessible only to the chosen.

That was in June. But when worshippers return to the synagogue, in Miami’s Roads section, for Rosh Hashana, they’ll find the bima opened up to a broad, welcoming expanse.

Layers of shallow steps evoking shore-bound ocean waves have, figuratively, washed away all obstacles between themselves, their rabbi, cantor and congregational leaders.

The sanctuary transformation is Miami’s oldest Jewish congregation’s 100th birthday present to itself, a major milestone in the evolution of a religious, educational and community institution founded in 1912 by a Key West merchant named Morris Zion.

The congregation is a historic amalgam of smaller congregations, and the “parent’’ of Temple Bet Shira, in Southwest Miami-Dade.

It’s no accident that in this season of spiritual rebirth, Rabbi Hector “Tate’’ Epelbaum calls the structural changes not a renovation, but a “renewal’’ for Beth David, which he joined in 2006.

“We tried last year a new experience: installing a temporary lower bima for the High Holy Days,’’ said Epelbaum, 52, an Argentine by way of Israel and Miami Beach’s Cuban Hebrew Congregation.

“We removed the first three rows of the sanctuary with the idea that the clergy and those who are speaking from the bima will be closer to the congregation — no barriers, no idea that the rabbi and cantor are higher and the congregation is on a lower level, symbolically speaking.’’

Worshippers, many the children and grandchildren — some the great-grandchildren — of earlier members, loved it and wanted a permanent change, he said.

“Beth David is in the blood of our members,’’ he said, a living example of Jews’ obligation to pass the faith from one generation to the next.’’

Ed Sachs, president of the temple’s board and a member since 1982, said that the 400-family congregation “has been talking about [renovating] for 15 years, so with us moving forward into a new century, it was time to get it done.’’

Rosh Hashana, the two-day Jewish New Year, begins at sundown on Sunday, when Beth David members will pray in the synagogue’s small chapel. The updated, 1,070-seat sanctuary, named for the late Walter and Ruth Falk, unveils on Monday morning, the first full day of the Jewish year 5773.

A fund that Ruth Falk created after her husband died in 1996 underwrote the work, the cost of which temple officers declined to reveal.

His mother established an endowment as “a down payment for the total renovation of the synagogue,’’ said son Joe Falk, 58, a past president. She attached no strings, so that any future board could decide when to dip in.

The time seemed right in 2012, “if you believe that the narrative of our 100-year [anniversary] is a celebration of the past but a commitment to the future,’’ said Falk, public policy advisor at the Akerman Senterfitt law firm. “It does show…to the Jewish community here in South Florida that we’re not going anywhere.’’