Albert Barnes Commentary Isaiah 45:15

"Verily thou art a God that hidest thyself, O God of Israel, the Saviour." — Isaiah 45:15 (ASV)

Verily thou art a God that hidest thyself - That is, who hides your counsels and plans. The idea is that God's ways seem dark until the distant event discloses his purpose. A long series of mysterious events also seem to follow one another, testing the faith of his people, and the reason for his actions cannot be seen. This remark seems to be made by the prophet, considering that God's dealings with his people in their long and painful exile would be inscrutable to them. However, a future glorious manifestation would disclose the nature of his designs and make his purposes known : My thoughts are not your thoughts, neither are your ways my ways (the notes at Isaiah 8:17).

The Saviour - Still the Saviour of his people, though his ways are mysterious and the reasons for his dealings are unknown. The Septuagint renders this: For thou art God, though we did not know it, O God of Israel the Saviour. This verse teaches us that we should not grumble or complain under the mysterious allotments of Providence. They may be dark now. But in due time they will be disclosed, and we will be permitted to see his design and to witness results so glorious as to satisfy us that his ways are all just, and his dealings right.