"Two months earlier, in September of 1868, a camp meeting was held in Wright, Michigan. This gathering, the first of its kind, proved such a great blessing to those who attended that the following years witnessed the establishment of camp meetings as a regular part of the program for the state conferences. Elder and Mrs. White's presence was called for, and so it came that the summer months in succeeding years were largely spent by them in these annual gatherings. In the latter part of volume 2 may be found counsel regarding such “convocations.” 2T 6.2"
"And the apostles and elders came together for to consider of this matter."
Both passages refer to gatherings of religious leaders and members for discussion and counsel. While Acts 15:6 describes a specific council of apostles and elders, the EGW passage discusses camp meetings. The connection lies in the shared theme of religious convocations for deliberation and spiritual growth.
"But, with all these gains and advance moves, the adversary continued to work earnestly to lower the spirituality of church members, to cause them to love the world and its attractions, to leaven the church with the spirit of criticism, to dry up the springs of benevolence, and especially to bring the youth into his ranks. Against these dangerous trends Mrs. White, as God's messenger, was faithfully and earnestly delivering her messages by voice and pen, calling the members of the church to God's standard of integrity and righteousness. 2T 6.4"
"Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour:"
Both passages warn against the influence of the adversary (devil/Satan) and the need for vigilance. The EGW passage describes Satan's methods, while 1 Peter 5:8 warns of his presence.