"When my turn came to speak, I stated the evidences I enjoyed of Jesus’ love, and that I looked forward with the glad expectation of meeting my Redeemer soon. The belief that Christ's coming was near had stirred my soul to seek more earnestly for the sanctification of the Spirit of God. LS 46.1"
"And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ."
Both passages connect the coming of Christ with sanctification. The EGW passage describes how the belief in Christ's coming motivated her to seek sanctification, while 1 Thessalonians 5:23 prays for complete sanctification until Christ's coming. The connection is valid.