... forbidden to evaluate myself on the basis of my own feelings ...

"Through faith in God's Word I say that if sin is present, it does not matter to me. 

I have been forbidden to evaluate either myself on the basis of my own feelings, or the church on the basis of external appearance. 

I have been commanded to judge by the Word of promise. 

The gospel says and teaches something different from my senses. It says that there is One who 'committed no sin, neither was deceit found in his mouth' (1Pt 2:22).

In Himself He has conquered death, the world, and sin. He has said: 'Take heart; I have overcome the world."' (Jn 16:33); 'Sin will have no dominion over you' (Rm 6:14); and similar statements in Holy Scripture. 

Him alone I know, and this I know, too, that He has been appointed the Bridegroom and has conveyed to His bride, the church, [ and thus to me] all that He has. 

I am a part of His church. 

For I have sure signs and pledges, namely: baptism, the gospel, the Lord’s Supper, that witness to the fact that I am a member of Christ.

"This comfort and knowledge is so great that it cannot be understood so quickly as I wish it could be. 

If we could grasp it completely, we would never be stirred by any sense of death or sin. 

Our failure to understand this fully makes our conscience vex us, dangers disturb us, the remembrance of death and afflictions frighten us. 

This failure lies in our comprehension; it does not lie in Christ. 

It is like a man who has fallen into the middle of a stream. He catches the branch of a tree somehow to support himself above the water and be saved. 

So in the midst of sins, death, and anxieties we, too, lay hold on Christ with a weak faith. 

Yet this faith, tiny though it may be, still preserves us and rules over death and treads the devil and everything under foot."

Martin Luther

Lecture on Psalm 45, 9