Though not without misgiving the writer has resolved to advance to perfection i.e. to the exposition of Christian truth in its higher development, and to take for granted the knowledge of the bare elements. But he thinks it well at the outset to remind his readers of those elements, apart from which there can be no progress in religion. The subjects which he regards as primary are arranged in three pairs: (a) Repentance and faith; men must learn the meaning of these before they can even enter on the Christian life. (b) Baptisms and the laying on of hands; for by these rites the new spiritual gifts are imparted. The plural baptisms may refer to the double consecration by water and the Spirit, or it may suggest that Christians have to learn the difference between their own rite and heathen or Jewish baptisms. (c) Resurrection and judgment: the two great facts which gave meaning to the Christian hope. The writer proposes, with the help of God's grace, to advance beyond these preliminary truths (Hebrews 6:3); if his readers have forgotten them, all his labour is thrown away. Conversion is an experience that cannot be repeated. Those who have once experienced the Divine gift of forgiveness, who have been renewed by the work of the Holy Spirit, who have realised the value of God's promise and shared in the higher activities of the Christian life, cannot be restored if they fall away. They have rejected Christ just as truly as the men who crucified Him, and have shamed Him before the world by their apostasy. It is with men as it is with waste land that has been reclaimed. The land that proves fruitful will become ever richer, while that which yields nothing but weeds, in spite of all the labour spent upon it, has to be given back again to the waste.