God has always tried His people in the furnace of affliction. It is in the heat of the furnace that the cross is separated from the true gold of the Christian character. Jesus watches the test; He knows what is needed to purify the precious metal, that it may reflect the radiance of His love. It is by close and testing trials that God disciplines His servants. He sees that some have powers which may be used in the advancement of His work and He puts these persons upon trial; in His Providence, He brings them into positions that test their character and reveal defects and weaknesses that have been hidden from their own knowledge. He gives them opportunity to correct these defects and to fit themselves for His service. He shows them their own weakness and teaches them to lean upon Him, for He is their only help and safeguard. Thus, His object is attained. They are educated, trained, and disciplined, prepared to fulfill the grand purpose for which their powers were given them. When God calls them to action, they are ready and heavenly angels can unite with them in the work to be accomplished on Earth. Patriarchs & Prophets pg. 129,130

Men whom God favored and to whom He entrusted great responsibilities were sometimes overcome by temptation and committed sin, even as we at the present day strive, waver, and frequently fall into error. Their lives, with all their faults and follies, are open before us, both for our encouragement and warning. If they had been represented as without fault, we, with our sinful nature, might despair at our own mistakes and failures. But seeing where others struggled through discouragements like our own, where they fell under temptations as we have done, and yet took heart again and conquered through the grace of God, we are encouraged in our strive for righteousness. As they, though sometimes beaten back, recovered their ground and were blessed by God so we too may be overcomers in the strength of Jesus. On the other hand, the record of their lives may serve as a warning to us. It shows that God will, by no means, clear the guilty. He sees sin in His most favored ones and He deals with it in them even more strictly than in those who have less light and responsibility.  Patriarchs & Prophets pg. 238

In all who have been chosen to accomplish a work for God, the human element is seen. Yet they have not been men of stereotyped habits and character who were satisfied to remain in that condition. They earnestly desired to obtain wisdom from God and to learn to work for Him. Says the apostle, "If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him." James 1:5. But God will not impart to men divine light while they are content to remain in darkness. In order to receive God's help, man must realize his weakness and deficiency; he must apply his own mind to the great change to be wrought in himself; he must be aroused to earnest and persevering prayer and effort. Wrong habits and customs must be shaken off and it is only by determined endeavor to correct these errors and to conform to right principles that the victory can be gained. Many never attain to the position that they might occupy because they wait for God to do for them that which He has given them power to do for themselves. All who are fitted for usefulness must be trained by the severest mental and moral discipline and God will assist them by uniting divine power with human effort.  Patriarchs & Prophets pg. 248