Comprehensive guide to writing an invitation letter for your US visa application, with free samples and tips. The letter should include specific details like your relationship with the visitor, the purpose of their visit, duration of stay, and financial arrangements.Temporary religious worker (R-1) visas are for persons who want to work temporarily in the United States in religious capacities. In this extensive guide, we'll walk you through the steps of creating a compelling invitation letter for your US visa application. Can the church provide you an invitation letter to watch general conference if you are not living in the United States to apply for a visa? How to Write a Letter of Invitation for a U.S. Visa Application? Complete the Invitation Letter form. Fill out the form with correct and sincere information about you, your guest, and the entry and departure date.