Just as I am is typically used as an invitational hymn in services where people in the audience are invited to come to the alter for communion and joining the membership, and other events. However the message is not exclusively for these, and can serve a wider purpose such as an invitation to become a student of Jesus’ teachings, as in the Parables.
The following is by Alan Jackson
The hymn was written by Charles Elliot in 1835 and more history is given at https://en.wikipedia.org/wiki/Just_As_I_Am_(hymn).