Verse 3. Thou therefore endure hardness, as a good soldier of Jesus Christ. Such hardships as a soldier is called to endure. The apostle supposes that a minister of the gospel might be called to endure hardships, and that it is reasonable that he should be as ready to do it as a soldier is. On the hardships which he endured himself, See Barnes "2 Co 11:23-29".

Soldiers often endure great privations. Taken from their homes and friends; exposed to cold, or heat, or storms, or fatiguing marches; sustained on coarse fare, or almost destitute of food, they are often compelled to endure as much as the human frame can bear, and often, indeed, sink under their burdens and die. If, for reward or their country's sake, they are willing to do this, the soldier of the cross should be willing to do it for his Saviour's sake, and for the good of the human race. Hence, let no man seek the office of the ministry as a place of ease. Let no one' come into it merely to enjoy himself. Let no one enter it who is not prepared to lead a soldier's life, and to welcome hard, ship and trial as his portion. He would make a bad soldier, who, at his enlistment, should make it a condition that he should be permitted to sleep on a bed of down, and always be well clothed and fed, and never exposed to peril, or compelled to pursue a wearisome march. Yet do not some men enter the ministry, making these the conditions? And would they enter the ministry on any other terms?

{d} "hardness" 1 Ti 1:18