Lord Jesus Christ,
truly I am not worthy that you should come under my roof,
yet I need your help and desire your grace,
that I may attain godliness and salvation.
I come now in no other confidence than this,
that I have heard the sweet words of your invitation to your table,
and though I am unworthy, you promised me
forgiveness of my sins through your body and blood
which I eat and drink in this Sacrament.
O dear Lord, I know that your divine Word and promise are true.
I do not doubt them,
and resting on them,
I eat and drink with you.
Let it be to me according to your word.
Amen.
Source: Martin Luther
Source of this version: Modified from Prayers from the collection of the late baron Bunsen, selected [from Versuch eines allgemeinen evangelischen Gesang – und Gebetbuchs] and tr. by C. Winkworth, 1871, p.182
Picture by James Tissot, public domain
Variant:
Lord, it is certainly true that I am unworthy to have you come under my roof, but I am so needy and long for your help and grace so that I may become righteous. Therefore, I come to you, trusting in nothing other than the sweet words which I have heard, with which you invite me to your Table and say to me, who am so unworthy, that I will receive forgiveness of my sins through your Body and Blood if I eat and drink of them in this Sacrament. Amen! Dear Lord, your word is true; this I do not doubt; and on this promise I eat and drink with you; let it be to me according to your will and word. Amen.
Source: Modified from http://www.godrules.net/library/luther/NEW1luther_f7.htm
A Collection of Prayers 