Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy strength, and with all thy mind; and thy neighbour as thyself. Luke 10:27. TDG 52.1
The heart is the citadel of the whole man, and until the heart is wholly on the Lord's side, the enemy will find unguarded entrances through which he can take possession. “Work out your own salvation with fear and trembling. For it is God which worketh in you both to will and to do of his good pleasure” (Philippians 2:12, 13). If you would have light, you must intelligently cherish it, and constantly exercise faith, and not be controlled by feeling. It is evident that truth has been planted in the heart by the Holy Spirit when it is loved and cherished, and regarded as a sacred endowment. Love will then spring up in the heart like a well of living water, springing up unto everlasting life. When this love is in the heart, the worker will find no weariness in the work of Christ. TDG 52.2
Let not one ray of light from heaven be held in questioning and doubt. In great power the Lord has revealed to you His grace, His mercy, and His love; and He who charges the work of God to undue excitement, and calls it fanaticism, is certainly standing on dangerous ground. If such do not retrieve their steps, their consciences will become less and less sensitive, and they will have less and less appreciation of the Spirit of God. It will become harder and harder for them to understand the message of God. Why?—Because they are sinning against the Holy Ghost; and as a result of their resistance, they place themselves where they cannot recognize the Spirit of God, but set themselves against every instrumentality that God might use to save them from ruin. “What sign shewest thou?” (John 2:18) said the Jews to Christ, when at the same time His life and character, His lessons and miracles, were continual signs of His holy mission and divinity. TDG 52.3
When God moves upon the hearts of men to draw them to Christ, it seems that a compelling power comes over them, and they believe, and give themselves up to the influence of the Spirit of God. But if they do not maintain the precious victory that God has given; if they permit old practices and habits to revive, and indulge in amusement or worldly luxury; if they neglect prayer, and cease resisting evil, then Satan's temptations are accepted, and they are led to doubt the verity of their former experience.—The Review and Herald, February 13, 1894. TDG 52.4