As to how God is portrayed, some critics say that Faustus confuses the Old Testament representation of a vengeful God with the New Testament merciful God and fails to seek forgiveness because of this confusion. Other critics hold that this position isn't supported in the text. Faustus's conversations with the Old Man indicate a clear understanding and portrayal of Christ as the emissary of a merciful, forgiving God. Further, Faustus's last speech portrays God clearly as a loving God who is ever present with the offer of forgiveness.
FAUSTUS. See, see, where Christ's blood streams in the firmament!
One drop would save my soul, half a drop: ah, my Christ!—
Ah, rend not my heart for naming of my Christ!
Yet will I call on him: O, spare me, Lucifer!—
Where is it now? 'tis gone: and see, where God
Stretcheth out his arm, and bends his ireful brows!
What keeps Faustus from seeking forgiveness is not a portrayal of God as vengeful but the other portrayal, the one of Lucifer, that is reflected in the same quote above: "[Lucifer, ah], rend not my heart for naming of my Christ!" What stops Faustus is the torment begun by Mephistophilis, begun even while Faustus is still alive and promised for after he is dead.
MEPHIST. Thou traitor, Faustus, I arrest thy soul
For disobedience to my sovereign lord:
Revolt, or I'll in piece-meal tear thy flesh.
FAUSTUS. ... God, whom Faustus hath blasphemed! Ah, my God, I would weep! but the devil draws in my tears. Gush forth blood, instead of tears! yea, life and soul! O, he stays my tongue! I would lift up my hands; but see, they hold them, they hold them!
The portrayal of God by the Old Man, the Three Scholars and the Good Angel offers an easier way of determining how God is portrayed since their portrayals are less confusing than the metaphysical interchanges between Faustus and Mephisto.
Scholars: They portray God as having limitless mercies and an unlimited readiness to forgive where forgiveness is sought.
SECOND SCHOLAR. Yet, Faustus, look up to heaven; remember God's mercies are infinite.
Old Man: He portrays God in a way that accords with and expands upon the Scholars portrayal. He declares God is offering His grace to Faustus and is ready to give it freely. All that is required is a contrite heart and tears of repentance.
OLD MAN. ... I see an angel hovers o'er thy head,
And, with a vial full of precious grace,
Offers to pour the same into thy soul:
Good Angel: The Good Angel is the bearer of the message of sin and blasphemy to Faustus. Later though, the Angel promises God's pity and mercy.
GOOD ANGEL: And heap God's heavy wrath upon thy head! ... that is blasphemy! ... Faustus, repent; yet God will pity thee.