These things have I written unto you, that ye may know that ye have eternal life, even unto you that believe on the name of the Son of God.
These things I write so you who believe in Christ's name for righteousness, life, and salvation might know you have eternal life in Him and a right to it. The assurance comes by faith under the Spirit's testimony, and you ought to be encouraged to continue believing in Him and hold fast to Him.
AI summary
The believer carries inward proof: he has seen his sin and need, beheld Christ's excellency and suitableness to it, felt the power of His word remaking him, and discovered love kindled to God through this revelation. That is testimony no argument can shake.
AI summary
Commenting on 1 John 5:10-13
I have written this epistle so that you who believe on the name of the Son of God may know that you have eternal life. To know that we have eternal life is the sure way to joy in God.
AI summary