Each mark requires its own trial.
The Mark of the Pilgrim is reserved for those who pass the Trial of the Pilgrim. You must be above level 35 to qualify. To take this test visit the Hermit Santiago in the Estate of Gludio. He lives on a farm with Piotur.
The Mark of Life is reserved for those who pass the Testimony of Life. You must be above level 37 to take the test. To take this trial, visit Master Cardien of the Town of Dion.
And last, the Mark of the Healer is reserved for those who pass the Test of the Healer. You must be above level 39 to qualify. To take the Test of the Healer, visit Priest Bandellos in the temple of the Town of Giran.