because of the truth that remains in us and will be with us forever.2 John 1:2(HCSB)
John is often called 'the apostle of love', and here he expressed his Christian love in a short letter to the 'elect lady' and her children because they were all born of the Spirit, children of God, one with the Lord, positioned in Christ, and part of His Body which is the Church. John rejoiced because like him, they were accepted in the Beloved, indwelt by the Holy Sprit, seated in heavenly places, and walking in spirit and truth.
John rejoiced because the truth of the glorious gospel of grace abode, remained, and rested in the heart of this precious sister in Christ and her family (as it does in all who have been saved by grace through faith in Christ), and John gave additional assurance that this gospel truth would remain with them all forever.
But John was also an apostle that held fast to the unchanging and unchangeable truth of God's Word and the love that he expressed for this woman, and all who would read this short epistle, is one of godly concern that none of us stray from the truth of God's Word, together with a reassurance that the Word of truth which abides in us will be with us through time and into eternity.
We are called on many occasions to love others as Christ loved us, and the aging apostle John demonstrated deep love for all believers by speaking to them often of the gospel of Christ, encouraging them in their Christian walk, reminding them to hold fast to that which is good, and warning them of against straying from the truth of the gospel of Christ.
John knew that shortly before Christ's crucifixion, the Lord Jesus reminded them that He is the only Way, the only Truth, and the only Life, and that the Holy Spirit of truth Who indwells all believers, has promised to guide us into all truth. John also knew that the sum of God's Word is truth and His truth stands fast forever and ever. John knew that God has placed His Word above His holy name and so John could boldly proclaim to this sister in Christ: "I love all of you in the truth and not only I, but also all who have come to know the truth, because of the truth that remains in us and will be with us forever."
Heavenly Father, I praise and thank You for the truth of Your Word and the Holy Spirit Who dwells in me. Thank You for Your promise that He will guide me into all truth. Thank You for Jesus Who is the Way, the Truth, and the Life. In His precious name I pray, AMEN.