Charlotte De Kesel, a Christian living in Brussels, told Premier's News Hour that she will not let it stop her living life. Speaking after her visit to church following the Paris attacks she said: "I was really surpised and happy that the church was full, a very lively service and people were full of hope, and that's the most important thing."
Police are questioning 21 people after a series of raids in Belgium.
Raids across the capital on Sunday capped a tense day with hundreds of troops patrolling the streets and authorities hunting suspected extremists, including Salah Abdeslam, a fugitive since being named as a key suspect in the November 13th Paris attacks.
The Belgian government chose to keep Brussels on the highest state of alert into the start of the working week after what it described as a "serious and imminent" threat.
Charlotte De Kesel told Premier that normal life is attempting to go ahead: "There are people on the street, but obviously far less than usual.
"Most people I know went to work or tried to carry on working from home, but the fact is that schools are closed so we have to find a solution for the children."
France has intensified its aerial bombing in Syria and defence minister Jean-Yves Le Drian said the aircraft carrier Charles de Gaulle - which has been sent to the Mediterranean to help combat IS militants in Syria - will be "operational" from Monday and "ready to act".
France has also extended a state of emergency - which allows police raids, searches and house arrest without permission from a judge, for three months.
Listen to Premier's Hannah Tooley speak to Charlotte De Kesel, a Christian living and working in the city, here: