We cannot argue the fact that your father-in-law is a blessing in your life. His presence has made your life better in more ways than you can imagine. Appreciate him, send this ecard on his upcoming birthday.
Today is the day to say 'thank you' to your father-in-law for being such a great role model to you. The fact that he has embraced you into his family is an action that you need to appreciate more. So send this ecard on his birthday.