William Carey quotes

Many can do nothing but pray, and prayer is perhaps the only thing in which Christians of all denominations can cordially, and unreservedly unite; but in this we may all be one, and in this the strictest unanimity ought to prevail. Were the whole body thus animated by one soul, with what pleasure would Christians attend on all the duties of religion, and with what delight would their ministers attend on all the business of their calling.
We must not be contented however with praying, without exerting ourselves in the use of means for the obtaining of those things we pray for. Were the children of light, but as wise in their generation as the children of this world, they would stretch every nerve to gain so glorious a prize, nor ever imagine that it was to be obtained in any other way.

Our Lord Jesus Christ, a little before his departure, commissioned his apostles to Go, and teach all nations; or, as another evangelist expresses it, Go into all the world, and preach the gospel to every creature. This commission was as extensive as possible, and laid them under obligation to disperse themselves into every country of the habitable globe, and preach to all the inhabitants, without exception, or limitation. They accordingly went forth in obedience to the command, and the power of God evidently wrought with them.

The most glorious works of grace that have ever took place, have been in answer to prayer; and it is in this way, we have the greatest reason to suppose, that the glorious out-pouring of the Spirit, which we expect at last, will be bestowed.

Yet God repeatedly made known his intention to prevail finally over all the power of the Devil, and to destroy all his works, and set up his own kingdom and interest among men, and extend it as universally as Satan had extended his. It was for this purpose that the Messiah came and died, that God might be just, and the justifier of all that should believe in him. When he had laid down his life, and taken it up again, he sent forth his disciples to preach the good tidings to every creature, and to endeavour by all possible methods to bring over a lost world to God.

Expect great things from God; attempt great things for God.

In one period the grossest ignorance and barbarism prevailed in the world; and afterwards, in a more enlightened age, the most daring infidelity, and contempt of God; so that the world which was once over-run with ignorance, now by wisdom knew not God, but changed the glory of the incorruptible God as much as in the most barbarous ages, into an image made like to corruptible man, and to birds, and four-footed beasts, and creeping things. Nay, as they increased in science and politeness, they ran into more abundant and extravagant idolatries.

The Missionaries must be men of great piety, prudence, courage, and forbearance; of undoubted orthodoxy in their sentiments, and must enter with all their hearts into the spirit of their mission; they must be willing to leave all the comforts of life behind them, and to encounter all the hardships of a torrid, or a frigid climate, an uncomfortable manner of living, and every other inconvenience that can attend this undertaking. … They must be very careful not to resent injuries which may be offered to them, nor to think highly of themselves, so as to despise the poor heathens, and by those means lay a foundation for their resentment, or rejection of the gospel. They must take every opportunity of doing them good, and labouring, and travelling, night and day, they must instruct, exhort, and rebuke, with all long suffering, and anxious desire for them, and, above all, must be instant in prayer for the effusion of the Holy Spirit upon the people of their charge. Let but missionaries of the above description engage in the work, and we shall see that it is not impracticable.
It might likewise be of importance, if God should bless their labours, for them to encourage any appearances of gifts amongst the people of their charge; if such should be raised up many advantages would be derived from their knowledge of the language, and customs of their countrymen; and their change of conduct would give great weight to their ministrations.

As our blessed Lord has required us to pray that his kingdom may come, and his will be done on earth as it is in heaven, it becomes us not only to express our desires of that event by words, but to use every lawful method to spread the knowledge of his name. In order to this, it is necessary that we should become, in some measure acquainted with the religious state of the world; and as this is an object we should be prompted to pursue, not only by the gospel of our Redeemer, but even by the feelings of humanity, so an inclination to conscientious activity therein would form one of the strongest proofs that we are the subjects of grace, and partakers of that spirit of universal benevolence and genuine philanthropy, which appear so eminent in the character of God himself.

If the prophecies concerning the increase of Christ's kingdom be true, and if what has been advanced, concerning the commission given by him to his disciples being obligatory on us, be just, it must be inferred that all Christians ought heartily to concur with God in promoting his glorious designs, for he that is joined to the Lord is one spirit.
One of the first, and most important of those duties which are incumbent upon us, is fervent and united prayer. However the influence of the Holy Spirit may be set at nought, and run down by many, it will be found upon trial, that all means which we can use, without it, will be ineffectual. If a temple is raised for God in the heathen world, it will not be by might, nor by power, nor by the authority of the magistrate, or the eloquence of the orator; but by my Spirit, saith the Lord of Hosts.