[1] After Elias, Mendelssohn was searching for a libretto for a new oratorio and consulted a number of scholars for inspiration, among them Julius Schubring, Johann Gustav Droysen and Henry Chorley.

It is thought that certain material from Mendelssohn's embryonic composition was included in his oratorio Erde, Hölle und Himmel, possibly the third number, "Es wird ein Stern aus Jacob aufgeh'n".

[1] The existing fragments of Christus comprise 16 movements for choir and solo voices, relating the Biblical accounts of the Nativity and Passion of Jesus.

Music scholars have compared it to Felix Mendelssohn's earlier work Erde, Hölle und Himmel ("Earth, Hell and Heaven") and surmise that the completed movements of Christus were intended to form the Erde part of a larger work, to be followed two more unrealised sections concerned with the Crucifixion, Christ's descent into Hell and Resurrection (Hölle), and the Last Judgment (Himmel).

[4] Jeffrey S. Sposato discusses both Christus and Mendelssohn's cuts in his performing version of J. S. Bach's Matthäuspassion and claims to discern an agenda in the latter to promote "the Lutheran concept of universal guilt for Christ's death" in a manner consistent with anti-Jewish sentiment, which he was able to transcend with genuine Christian sincerity in the former.