Have ye suffered so many things in vain?
The vanity of past Christian life in the case of apostasy
Unless you continue faithful to the end, all your former Christian life must remain without the recompense God longs to bestow. Your struggles, your self-sacrifice, will all be unrewarded. The apostasy of the closing days of your life would render worthless the fidelity of all your previous years. You have done so well, that if now you do not fail you will have an abundant entrance into glory. It is not God’s will that any who have suffered with Christ should miss the honour and blessedness of reigning with Him. (R. W. Dale, LL. D.)
The power of hopefulness
It is worthy of consideration on the part of all who are entrusted with the moral and religious care of others, that throughout Holy Scripture there is the union of kindly loving hopefulness with strong and even stern rebuke. If in despair of men who have gone grievously wrong, they will soon despair of themselves. Those who have been most successful in prevailing others to trust in Christ have commonly had an ardent and unconquerable persuasion that they should succeed; the eager faith of their own hearts has passed into the hearts of those with whom they pleaded. (R. W. Dale, LL. D.)
Use of adversity
As the skilful pearl-seller and cunning lapidary doth willingly suffer the Indian diamond or adamant to be heavily smitten, because he knoweth well the hammer and anvil will sooner be bruised than the diamond or adamant be broken; so our most wise God suffereth men of excellent virtues, of unquenchable love and charity, and invincible constancy, to fall into divers temptations, great afflictions, and manifold miseries, because He will have their moral grace to break out and shine before men, that they, seeing the constancy of His saints, may glorify God which is in heaven. (Cawdray.)
Backsliders run in vain
The philosopher, being asked in his old age why he did not give over his practice, and take his ease, answered, “When a man is to run a race of forty furlongs, would you have him sit down at the nine-and-thirtieth, and so lose the prize? We do not keep a good fire all day, and let it go out in the evening, when it is coldest; but then rather lay on more fuel, that we may go warm to bed.” He that slakes the heat of his zeal in old age will go cold to bed, and in a worse case to his grave. Though the beginning be more than half, yet the end is more than all. (Spencer.)