The Reverend Aftab Gohar of Abbotsgrange Parish Church in Grangemouth, near Falkirk, gave a dedication service to Boys' Brigade and Girls' Brigade members.
This was despite knowing two of his brother's children - an 11-year-old girl and a nine-year-old nephew - had been killed along with other family members in the attack on All Saints' Church in Peshawar.
Afterwards, he heard his mother was also among the 85 people killed.
Rev Gohar, 45, who was born in Peshawar, in the shadows of the Himalayas, returned immediately to Pakistan, along with his wife Samina, and recited a prayer for the dead during a memorial service at the city's cathedral.
He said: "I didn't want to disappoint the youth organisations. I came to know about these children, my uncle and my cousins, but I went to church.
"After the dedication service for the Boys' Brigade and Girls' Brigade, when I came out of the church, I came to know about my mum as well. Within one or two hours we arranged our journey and travelled to Pakistan. It's a very big tragedy in our family."
Mr Gohar's brother, Ansar Gohar, was in the US when he found out his son and daughter had been killed. The children's mother is badly injured and has not been told the youngsters are dead as doctors believe she could not cope.
Devastated Ansar Gohar said: "I have no future, my children were my future. Everything has gone."
Rev Gohar, speaking from Pakistan, said: "On Monday we had three funerals in our house and many members of my family are in hospital.
"My parents were baptised in that church, we were baptised in the church. We loved that church and that's why I went there and participated in a memorial service, arranged by the diocese."
A spokesman for Falkirk Presbytery said: "Our thoughts and prayers are with Aftab and all his family, and indeed all who have been affected by this atrocity."
Mr Gohar was ordained in the Church of Pakistan in 1995, before travelling to Scotland in 1998 for a year of study. He and his family including sons Shahan, 17, and Zeeshan, 15, moved to Scotland in 2008 and he was inducted as Abbotsgrange's minister in February 2010. He is the first Pakistani minister in the area and only the third in Scotland.
A Church of Scotland spokesman said: "The Church of Scotland was shocked with the news of the suicide bomb attack at the historic All Saints' Church in Peshawar.
"Our shock and sorrow increased when we heard that Rev Aftab Gohar's mother was among the dead, along with two of his brother's children. Aftab grew up in All Saints' Church. Our condolences go to our friend and his family and to all who are grieving the loss of loved ones or recovering from injuries."
He said the extent of the bombing was becoming apparent.
The spokesman added: "Already stories are emerging that among those killed were leaders in the local Christian community, teachers, people who arranged scholarships for Christian students along with children and young people who should have their whole lives ahead of them.
"We are united in sorrow with our brothers and sisters in Peshawar and we give thanks for the lives of those who have been killed.
"The Church of Scotland is grateful for the many messages of sympathy already received and note particularly the statement from the Muslim Council of Scotland condemning the attack."
Two Islamist militant groups with Taliban links have said they ordered the attack to hit back at US drone strikes.