Does anything in Mrs. White’s writings say something to the effect that we have to live up to the light we already have or we will not receive new light?
Here are several statements that perhaps offer the kind of content you are looking for.
Let Christians who love duty lift every ounce they can and then look to God for further strength. He will work through the efforts of thoroughgoing men and women and will do what they cannot do. New light and power will be given them as they use what they have. New fervor and zeal will stir the church as they see something accomplished (Testimonies for the Church, 5:369).
Here is your danger, in failing to press forward “toward the mark for the prize of the high calling of God in Christ Jesus.” Has the Lord given you light? Then you are responsible for that light; not merely while its rays are shining upon you, but for all which it has revealed to you in the past. You are to surrender your will to God daily; you are to walk in the light, and to expect more; for the light from the dear Saviour is to shine forth in clearer, more distinct rays amid the moral darkness, increasing in brightness more and more unto the perfect day (ibid., 5:486).
With some the knowledge of their true state seems to be hidden from them. They see the truth, but perceive not its importance or its claims. They hear the truth, but do not fully understand it, because they do not conform their lives to it, and therefore are not sanctified through obeying it. And yet they rest as unconcerned and well satisfied as though the cloud by day and the pillar of fire by night, as token of God’s favor, went before them. They profess to know God, but in works deny Him. They reckon themselves His chosen, peculiar people, yet His presence and power to save to the uttermost are seldom manifested among them. How great is the darkness of such! yet they know it not. The light shines, but they do not comprehend it. No stronger delusion can deceive the human mind than that which makes them believe that they are right, and that God accepts their works, when they are sinning against Him. They mistake the form of godliness for the spirit and power thereof. They suppose that they are rich, and have need of nothing, when they are poor, wretched, blind, and naked, and need all things (ibid., 1:406, 407).
Whenever men are not seeking, in word and deed, to be in harmony with God, then, however learned they may be, they are liable to err in their understanding of Scripture, and it is not safe to trust to their explanations. When we are truly seeking to do God’s will, the Holy Spirit takes the precepts of His word and makes them the principles of the life, writing them on the tablets of the soul. And it is only those who are following the light already given that can hope to receive the further illumination of the Spirit. This is plainly stated in the words of Christ: “If any man will do His will, he shall know of the doctrine” (ibid., 5:705).