"This is the manner in which he would have us present his truth to others. The power of speech is of great value, and the voice should be cultivated for the blessing of those with whom we come in contact. I am pained when I see how little this precious gift is appreciated. In reading the Bible, in engaging in prayer, in bearing testimony, how necessary is clear, distinct utterance. How much is lost in family worship when the one offering prayer bows the face down, and speaks in a low, feeble voice, as though just recovering from a long sickness. But as soon as family worship is over, those who could not speak loud enough to be heard in prayer, can speak in clear, distinct tones, and there is no difficulty in hearing what is said. Prayer that is thus uttered is appropriate for the closet, but not suitable for public worship; for unless those assembled with them can hear what is said, they cannot say Amen. CE 127.1"
"If any man speak, let him speak as the oracles of God; if any man minister, let him do it as of the ability which God giveth: that God in all things may be glorified through Jesus Christ, to whom be praise and dominion for ever and ever. Amen."
Both passages address the manner of speaking, particularly in religious contexts. 1 Peter 4:11 emphasizes speaking "as the oracles of God," while EGW focuses on clear, distinct utterance in prayer and testimony. The underlying principle is the importance of effective communication in serving God.
Nearly all persons can speak loud enough to be heard in ordinary conversation, and why should not the same voice and talent be used when they are called upon to bear testimony or offer prayer? When speaking of heavenly and divine things, why not speak in distinct tones, in a manner that will make it manifest that you know what you are talking about, and are not ashamed to show your colors? Why not pray as though you had a conscience void of offense, and could come to the throne of grace in humility and yet with holy boldness, lifting up holy hands without wrath and doubting? Do not bow down and cover up your face as if there were something that you desired to conceal; but lift up your eyes toward the heavenly sanctuary, where Christ your Mediator stands before the Father to present your prayers as fragrant incense, mingled with his own merit and spotless righteousness. You are invited to come, to ask, to seek, to knock, and you are assured that you will not come in vain. Jesus says “As…
"And I say unto you, Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you. For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened. If a son shall ask bread of any of you that is a father, will he give him a stone? or if he ask a fish, will he for a fish give him a serpent? Or if he shall ask an egg, will he offer him a scorpion? If ye then, being evil, know how to give good gifts unto your children: how much more shall your heavenly Father give the Holy Spirit to them that ask him?"
Ellen White directly references Luke 11:9-13 in this passage.