On the anniversary of the father’s death, it helps to share a message of gratitude:
• For the good times he shared with them, contributing to the joy of family togetherness;
• For the discipline he administered which helped them grow up responsibly;
• For the example he gave them of how to appreciate the good and how to deal with the not-so-good;
• For whatever legacies he left behind.
The gratitude list can be as long as desired. It will help the family to focus on the pleasure of sharing his life, rather than the pain of losing him. The Bible verse I recommend (if they are believers) for reflection is 1 Thessalonians 1:3 (NIV): "We remember before our God and Father your work produced by faith, your labor prompted by love, and your endurance inspired by hope in our Lord Jesus Christ."
May they have many pleasant memories as they revisit their loss.