There are a number of Bible verses appropriate for use in a Christian thank you note or card, notes WhatChristiansWanttoKnow.com. One example is Numbers 6:24-26, which reads: "The Lord bless you and keep you; the Lord make his face to shine upon you and be gracious to you; the Lord lift up his countenance upon you and give you peace." A simpler thank you message with a Christian theme could be: "God blessed me with a friend like you," signing off with a religious sentiment such as "Blessings" or "God's blessings."
Some extracts from Bible verses suitable for expressing gratitude in a Christian thank you note include "The living, the living, he thanks you, as I do this day" (Isaiah 38:19), "Greater love has no one than this, that one lay down his life for his friends" (John 15:13), "The Lord repay you for what you have done" (Ruth 2:12) and "Now may the Lord show steadfast love and faithfulness to you. And I will do good to you because you have done this thing" (2 Samuel 2:6).
When writing a Christian thank you note, it is a good idea to use Christian-themed stationery or greetings cards, suggests OpposingViews.com. This could include stationery featuring, for instance, iconography such as the crucifix or Christ.