It is our job to get the word out but not to convert people. We are to tell the people how to get saved and about Gods unconditional love but God does the converting we just get the message out
The Lords Supper should be open to all believers no matter if they are a member of the church or not the only warning that should be given is the warning of still having sin. We need to confess our sins before we partake of the Lord's Supper. Amen.