The article deals with the pericope Gal 4.21-31 (thus it is delimited by the author) in which the apostle Paul once more uses arguments from the Old Testament to convince the recipients of the Letter of the right way to reach justification before God. Actual quotations of the Old Testament are only in the verses 27 and 30. However, in the first part of the pericope (4.22-26) Paul alludes to the story of Abraham's two sons and two wives adding the interpretative key in v. 24: 'these things are said allegorically'. Although there is no consensus among authors in what sense Paul applies this principle to the biblical texts it is preferable to see here rather a typological approach than a pure allegory because Paul does not certainly deny a real story in the text of Genesis. However, for Paul the decisive factor in interpreting biblical texts was the person and life of Jesus Christ. In this light we must also see the quotations of Isa 54.1 in v. 27 and Gen 21.10 in v. 30, even though Paul may have been influenced by the reading of these biblical texts in Jewish liturgy. As for Paul, so for all true believers in Christ, the gift of the freedom Christ has brought must remain living.