There Is A Fountain Filled With Blood

Ephesians 2
13 but now, in Christ Jesus, ye who sometime were far off are made nigh by the blood of Christ.
14 For he is our peace....

How do we know that a man, one of our forefathers, was indeed filled with the Holy Spirit and is worthy of our consideration? How do we know that we might rely on such a man for spiritual edification?

Hymn By William Cowper
There is a fountain filled with blood drawn from Emmanuel's veins;
And sinners plunged beneath that flood lose all their guilty stains.
Lose all their guilty stains, lose all their guilty stains;
And sinners plunged beneath that flood lose all their guilty stains.

Those are not necessarily difficult questions....