... no believer ought expect another person to make it possible for them to live their faith ...

Just as you cannot make out of the gospel a sacrifice or a work, so you cannot make a sacrifice or a work out of this sacrament [of the Lord's Supper]; for this sacrament is the gospel.
Therefore, in this matter no one can achieve anything for another person.
Each one must believe for himself just as I must believe all the Gospels for myself.
I cannot hear or believe or keep for anyone else so much as a single letter of the gospel, even as I cannot be baptized for anyone else.
In living the faith, no believer ought expect another person to make it possible for them to live their faith.
What wolves in sheep’s clothing put conditions upon others which must be met before one will worship and serve with such fellow believers.
Nothing manifests the falsity of one’s faith more than the conditions they set upon other or the church before they will do what saving faith freely and gladly does.
This is a rejection of the faith and Christ because it is a rejection of right worship and service out of love for God our Savior.
Yet when it comes to good works, that is serving,
I can always do to another person and for another person.
Indeed, I have to do them for somebody else or they are not good works.
For example, I can pray for you, serve you, work for you, suffer for you, and so forth.
There is a great difference between faith and good works, just as vast as the difference in value between the tree and the fruit.
Fruits disappear and return each year, but the tree remains always.
Faith also remains always, but works disappear. ...
Be careful, therefore, to stay on the track.
Don't let anyone pull you away from the Word through any statement of man … [Gal. 1:8].
"The elect will be led astray," says Christ [Matt. 24:24].
Therefore we cannot build on the mere word of one of the elect saints, without Scripture.
Christ has warned us faithfully enough, and our own experience has probably taught us, that saintly men can make mistakes and have made mistakes. ...
No good work can free us of our sins or give us grace or life or salvation.
But this sacrament [of Lord's Supper] does give life, grace, and blessedness, for it is a fountain of life and of blessedness.

-Martin Luther
The Adoration of the Sacrament Vol. 36]