Bishop Robert Innes said his hope and prayer is that negotiations between the UK government and the EU regarding the withdrawal take into account the needs of people in his diocese, a significant number of whom he described as "quite vulnerable".
The bishop - who serves English-speaking believers across the continent - warned many have used all their savings to retire and buy a rural property in countries such as Spain or France, and they might struggling to afford moving back to the UK if they needed to.
He also said a significant proportion are concerned about how their pensions, entitlement to healthcare and right to reside might be affected.
Bishop Canon Innes said: "Many of my people are very worried about their futures. I hope that their needs will be very much taken into account when the UK government negotiates with the EU for the future.
So, prayers and action on behalf on of some quite vulnerable people here on the continent [is needed]."
He went on to say the EU has been "very important for the diocese", allowing free movement and the recruiting of clergy without the need for work permits.
Bishop Canon Innes added he had no intention of moving his office out of Brussels, saying it is still the administrative centre of the EU, close to London and the Belgium city boosts very good transport links.
The Anglican Bishop of Europe said the Church can "absolutely" help in the UK's EU withdrawal process, adding: "There are committed Christians working in the EU. Institutionally, the Church has good links with the institutions; we are well-represented in Brussels and we can help create a climate of mutual understanding and respect."
Meanwhile, the UK's outlook was downgraded to "negative" by the credit rating agency Moody's, citing "a prolonged period of uncertainty" which could hit medium-term economic growth.
EU leaders appear keen for the UK to complete it's withdrawal from the bloc as soon as possible, with European Commission president Jean-Claude Juncker stating it was "not an amicable divorce".