For a Muslim, the most honorable and holiest pledge is the one which he has made with his Lord and Creator. Fulfilling this pledge doesn’t just mean following rituals but following Allah’s ﷻ way of life.
Islam sees the human being as a trustee of God on earth; it doesn’t regard the human being as a sinful being with sin as the centre of his life. Sin is present in human life but trust and responsibility is the concept that supersedes all other things!
In order for human beings to truly be the trustees of God on earth they must have a great deal of determination as it is not an easy trust. The Quran in (33:72) describes this trust as a responsibility which the earth, mountains and seas could not undertake! But the human chose to carry this challenging responsiblity. This responsibility is also expressed in surah Yaseen (60-61).
In brief, the most important application of this aspect of ‘Amaanah is for the individual to select the way of life which is in accordance with the will of his creator.