Here are 10 things your welcome letter or email to new members must include plus a template that can be customized for your organization. The Riverside Church in the City of New York.We are an interdenominational, interracial, international, open, welcoming, and affirming church and congregation. 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. Welcome to Riverside, where new hires are valued and supported. Join our dynamic team and discover exciting opportunities for growth and development. 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!