[Last name and first name]
[Address]
[Last name and first name]
[Address]
The [date]
[My dearest] [First name],
You are going through a difficult time right now and I would like to offer you my support. Life is full of trials that make us stronger. I know you will get through this because you are equipped to deal with [this break-up/ unemployment/ exam failure/ illness/ other]. This is a difficult time that many have gone through and you can overcome it with your perseverance, inner peace and [indicate the quality that seems appropriate to the ordeal]. Like a ship in the midst of a storm, be an unflappable captain, confident of your crew, for you know you will arrive safely.
When a door closes, a window opens to new opportunities: [this break-up/ this unemployment/ this exam failure/ this illness/ other] is a challenge before your new flight. See it not as a failure, but as a test of life that pushes your limits and teaches you to know yourself better. Fortune will smile on you again, so be patient and don't let it get you down, the future is ahead of you; you still have so many beautiful things to experience. See the beauty the world has to offer and don't dwell on this turmoil. You have already risen from [recall a previously overcome trial]. Be like the army at the Battle of the Marne that rose from chaos to victory.
Have faith in your lucky star and know that you are not alone. You have always shown faithful friendship, those for whom you were there are there for you in return. In your moments of doubt, call me and don't hesitate to confide in me, I hope that I will be able to give advice as valuable as yours. Stay positive and the solutions will come in due course.
Take a step back to find the right solutions, remember when you gave me such good advice [recall an ordeal overcome thanks to his or her optimism and advice]. If you want, we can go away for a few days [suggest an activity]. Think about the positive things that happen to you every day [recall a nice thing that happened, talk about your family success, highlight your qualities].
Hang in there and fight. Have hope, the sun is shining at the end of the tunnel.
[Friendly nickname or first name depending on the relationship].