We're so happy to welcome you to the family! 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. I wanted to share an open letter to my future daughter in law. Here are 10 things your welcome letter or email to new members must include plus a template that can be customized for your organization. " "Love just got real. 1. Enter the date at the top of the letter. A good welcome letter acts as a travel guidepointing members to key resources, highlighting benefits, and outlining simple next steps. Welcome to the DD Waivers Services page. Here are a few new church member letter templates.