In that day shall the LORD defend the inhabitants of Jerusalem; and he that is feeble among them at that day shall be as David; and the house of David shall be as God, as the angel of the LORD before them. He that is feeble among them - shall be as David - Here is a marked difference between Judaism and Christianity. So clear, full, and efficient shall be the salvation of believers under the Gospel that the feeblest among them shall be as strong, as full of courage, and as successful as David when he went against Goliath. The least in the kingdom of heaven was greater than John the Baptist.
And the house of David - as the angel of the Lord - The family the Church of the true David, the Lord Jesus, shall be as the angel of the Lord; shall stand in the Divine presence like Gabriel; for Christ hath said, "Blessed are the pure in heart, for they shall see God." So "we all, with open face beholding as in a glass the glory of the Lord, are changed from glory into glory, as by the Spirit of the Lord." Thus the house of David, the true Christians, shall here walk with, after, and before God.