Paul himself applied Isaiah 54:1 to the Church.
Our Lord’s thought dwells constantly in that circle of ideas to be found in the Old Testament concept of sacrifice and supremely in Isaiah liii. This culminates in the Last Supper. What Jesus does and says there is “the focus of revelation, in which the Old Testament and the New are one “. The meaning of His death as propitiation is demonstrated there, “for propitiation is merely a mode of mediation, a mode of it, no doubt, which brings home to us acutely what we owe to the Mediator, and makes us feel that, though forgiveness is free to us, it does not cost Him nothing ”. There follows a chapter on the earliest Christian preaching, in which the commission to baptize and to proclaim forgiveness of sins is shown to have meaning only in relation to Christ’s death. Both baptism and remission of sins were two forms of the same thing and inseparably linked. Our Lord’s death is everywhere interpreted in terms of Isaiah liii. and the Sacraments (than which, says Denney, “there is nothing in Christianity more primitive “) are witnesses to the connection between the Cross and forgiveness. – James Denney
The verse stated in Isaiah 54:1 is extraordinary —
“Shout for joy, O barren one, she who has not given birth;
Break forth into joyful shouting and rejoice, she who has not gone into labor [with child]!
For the [spiritual] sons of the desolate one will be more numerous
Than the sons of the married woman,” says the Lord.”
Some have a pessimistic view of the world and of ourselves as the Church in it, believing that things will only get worse. Often this comes from a gloomy perspective of Scripture and understanding of how things will be when Jesus returns —
I tell you that He will defend and avenge them quickly. However, when the Son of Man comes, will He find [this kind of persistent] faith on the earth?” – Luke 18:8
Many use this verse as a justification for an unbelieving heart.
Isaiah 54:1 is a promise for us to expect the present and coming worldwide harvest into the Kingdom.
This prophecy in Isaiah 54:1 had special meaning for the time at Pentecost. Maybe Jesus was thinking about this moment when He promised that the gates of Hades would not prevail against the Church.
Jesus told us plainly that the world would become a most unpleasant place and evil will multiply and even apparently triumph, but at the same time His people will multiply and spread across the face of the earth. Everything is heading for a climax – both evil and good. – John Piper
When we look at a graph showing the spread of Christianity, the command of Jesus in Mark 16:15 – that the gospel will be preached to every person – is at last attainable in our own times. Exposure to the gospel is an inadequate first step, but a necessary precursor to the discipling and church planting ministries which we find in Matthew 28:18-19.