Again God will have this violence and striving, as a character of difference, to shew who are bastard professors and who are not; who will go to the price of Christianity, and who will not. If men will go to heaven they must be violent, they must be at the cost and charges, sometimes to venture life itself, and whatsoever is dear and precious in the world. A man must be so violent, that he must go through all even death itself, though it be a bloody death, to Christ. This discards all lukewarm carnal professors, who shake off this violence. In all estates of the church, it is almost equally difficult to be a sound Christian; for God requires this violence even in the most peaceable times. Now, the truth and religion are countenanced by the laws, yet the power of it is by many much opposed. Therefore he now that in spite of reproach, in spite of slander, will bear the scorns cast upon the gospel, that will 'go with Christ without the gate, bearing his reproach,' Heb. xiii. 13, such a man may be said to be thus violent. It is an easy thing to have so much Christianity as will stand with our commodity or with pleasure, &c.; but to have so much as will bring us to heaven, I say it is equally hard in all times of the church, it requires violence to carry us through these lesser oppositions. . . . So that it be violence that hath eyes in its head, violence guided with judgment, from the knowledge of the excellency of the good things of the gospel, I speak of such a violence as that.
"From the days of John the Baptist until now the kingdom of heaven has suffered violence,[a] and the violent take it by force." - Matthew 11:12. One of my favorite verses. And somewhere, something I read pointed me towards this. Brilliance by Richard Sibbes.