What is the patience of the saints?
The patience of the saints is the God given capacity to righteously endure persecution, trials, and tribulation without murmuring, while keeping the commandments of God and the faith of Jesus, all the way to the end of the church age, even through the time of the mark of the beast.
Scripture describes the patience of the saints as the steadfast endurance of God's people who refuse to worship the beast or receive his mark, and who instead keep the commandments of God and the faith of Jesus. Revelation says, "Here is the patience of the saints: here are they that keep the commandments of God, and the faith of Jesus" (Revelation 14:12), and again, "He that leadeth into captivity shall go into captivity: he that killeth with the sword must be killed with the sword. Here is the patience and the faith of the saints" (Revelation 13:10). This patience is not passive waiting, but a righteous enduring of persecution, trials and tribulations inside real circumstances and relationships, without complaining, and with a joyful expectation of prevailing faith in Jesus Christ.
This patience is called "the word of His patience" in Revelation 3:10, where the Lord promises, "Because thou hast kept the word of my patience, I also will keep thee from the hour of temptation, which shall come upon all the world, to try them that dwell upon the earth." It is developed through tribulation itself, as Romans teaches: "we glory in tribulations also: knowing that tribulation worketh patience; And patience, experience; and experience, hope" (Romans 5:3-4). The trials, sufferings and afflictions the saints pass through are the very means by which this patience is formed in them by the Holy Ghost.
The patience of the saints is also tied directly to the reign of the Antichrist and the days of the beast. The saints will be present during that time of testing, purging and proving, when the Antichrist is given power to persecute and even kill the people of God, and it is in that hour that the Lord will know whether His people will wait upon Him and remain steadfast in His Word. James 1:4 sums up the goal of this patience: "let patience have her perfect work, that ye may be perfect and entire, wanting nothing." To have this patience is to have received the very life, testimony and patience of the Lord Jesus Christ, since to reject patience is, in effect, to reject the life of Christ given to the believer.
Ultimately, the patience of the saints is what carries the church through the sorrows and woes that come before the Millennium, giving hope, comfort and the assurance that redemption is found in waiting on Christ, no matter what persecution, affliction or death may come.
The scriptures
Because thou hast kept the word of my patience, I also will keep thee from the hour of temptation, which shall come upon all the world, to try them that dwell upon the earth. Behold, I come quickly: hold that fast which thou hast, that no man take thy crown.
He that leadeth into captivity shall go into captivity: he that killeth with the sword must be killed with the sword. Here is the patience and the faith of the saints.
And the third angel followed them, saying with a loud voice, If any man worship the beast and his image, and receive his mark in his forehead, or in his hand, The same shall drink of the wine of the wrath of God, which is poured out without mixture into the cup of his indignation; and he shall be tormented with fire and brimstone in the presence of the holy angels, and in the presence of the Lamb: And the smoke of their torment ascendeth up for ever and ever: and they have no rest day nor night, who worship the beast and his image, and whosoever receiveth the mark of his name. Here is the patience of the saints: here are they that keep the commandments of God, and the faith of Jesus.
And not only so, but we glory in tribulations also: knowing that tribulation worketh patience; And patience, experience; and experience, hope: And hope maketh not ashamed; because the love of God is shed abroad in our hearts by the Holy Ghost which is given unto us.
But let patience have her perfect work, that ye may be perfect and entire, wanting nothing.
I John, who also am your brother, and companion in tribulation, and in the kingdom and patience of Jesus Christ, was in the isle that is called Patmos, for the word of God, and for the testimony of Jesus Christ.
From the books
This answer is drawn from these passages in the Mary Banks Faith Library.