The phrase "boundless strength" is correct and usable in written English.
You can use it to describe something that never runs out of power or energy. For example, "She drew on her boundless strength to complete the marathon."
Her dad finds boundless patience, strength and energy to implement the regime, I find it draining and usually take on the tedious mealtime feeds instead.
Dee was a woman of great strength, boundless energy and tremendous faith.
Edith was a person of great strength, boundless energy, and had many interests.
He was a man with boundless energy, great strength and integrity.
If you want to give yourself a super charge just 10 minutes out of your busy day -- then connect with Jose and you will experience boundless energy and strength.
Characterized by boundless energy and strength, her paintings represent her passion for meaning and truth, feistiness and defiance of limits, intimate acquaintance with suffering, and finally poignant acknowledgment of things as they are.
Her boundless good humor, compassion and strength were inspiring to all those whose lives she touched.
Andy's wisdom, insight, experience, and boundless energy were a source of strength to all Americans committed to security and peace in the Middle East.
As benefactor, advisor and source of wise counsel, Max's wisdom, insight, experience and boundless energy were a source of strength to all Americans committed to security and peace in the Middle East.
It's not a sublime song; the participants impress more as a glittering guest list than as performers, and yet the benevolent will, strength of mind and boundless resources driving the project are majestic.
