Due to the coronavirus pandemic, the thesis defence was conducted online. The topic of his work was Communication of Peace in the Interventions of John Paul II. and Cardinal Vinko Puljić during the 1992-1995 war in Bosnia and Herzegovina, which he made under the guidance of the mentor prof. Dr. Norbert González Gaitan.

Rev. Kustura was born in 1991. in Zenica, to parents Zdravko and Lidija, born Miljak, as the older of two children. He finished high school in his hometown in KŠC Sv. Pavao, after which he went to the Vrhbosna Theological Seminary and attended the KBF.

After his ordination to the priesthood in 2016., he was the parish vicar at Stup in Sarajevo, where he remained until the fall of 2017., when he went to study in Rome.

Since October 2012., he has been a contributor to Katolički tjednik, and later to the web portal nedjelja.ba.