Here are 10 things your welcome letter or email to new members must include plus a template that can be customized for your organization. A "thank you for joining" membership letter should include a personalized greeting to the new member.Use the member's first name in your salutation. Do you want new ways to welcome members into your church? Check out these top church membership welcome letter templates and best practices. Get help drafting the welcome letters to the new members of your nonprofit organization with these two useful writing templates! 1. Enter the date at the top of the letter. We have an overview of how to write a tenant welcome letter, what it should include and when to send it. We've also included a free template that you can use! A good welcome letter acts as a travel guidepointing members to key resources, highlighting benefits, and outlining simple next steps.