Summary: John wants to assure believers of the eternal life they possess and spur them on toward continued faith in Jesus Christ.
The Christian’s assurance concerning salvation (vs. 13)
“These things I have written to you who believe in the name of the Son of God, in order that you may know that you have eternal life.”
One of the purposes of John’s letter was to convince the unbelieving, Gnostic follower that Jesus was the Christ.
But here in chapter five John gives us another reason for this letter—it was to assure believers of the eternal life they possess and spur them on toward continued faith in Jesus Christ.
One of the first satanic attacks against the young believer is to cast doubt into his mind concerning his salvation.
The moment you repent (a turning away from your sins and turning to Jesus Christ), a spiritual transaction takes place. The Bible calls it the new birth. The Gospel of John, chapter three, calls it being “born again.”
Peter says you are called out of darkness into God’s wonderful light:
But you are a chosen people, a royal priesthood, a holy nation, a people belonging to God, that you may declare the praises of him who called you out of darkness into his wonderful light. (1 Peter 2:9)
Paul says that you are rescued from the domain of darkness and transferred into the kingdom of God’s beloved Son (Col 1:13).
You are now called a “Child of God;” a “saint;” a “beloved”
Eph 1:3 Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ,
Eph 1:4 just as He chose us in Him before the foundation of the world, that we should be holy and blameless before Him. In love
Eph 1:5 He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will,
Eph 1:6 to the praise of the glory of His grace, which He freely bestowed on us in the Beloved.
Eph 1:7 In Him we have redemption through His blood, the forgiveness of our trespasses, according to the riches of His grace,
Eph 1:8 which He lavished upon us. In all wisdom and insight
All these blessings had nothing to do with you. It was all by His grace! You couldn’t purchase it; the price was too high. You didn’t deserve it; you were a sinner. You couldn’t earn it; the cost was too great. You didn’t find salvation; you and I were the ones who were lost. Salvation had to be purchased for us and freely given to us.
If I couldn’t purchase it, I don’t have to worry about someone stealing it from me.
If I didn’t deserve it, I don’t have to worry about falling into a state of unworthiness and no longer meriting it.
If I couldn’t earn it, I don’t have to worry about wrestling with self-pride.
If I couldn’t find salvation, I don’t have to worry about losing it.
When God gives salvation to the repentant sinner, He doesn’t take it away. We can’t even give it back.
John 10:28 and I give eternal life to them, and they shall never perish; and no one shall snatch them out of My hand.
John 10:29 "My Father, who has given them to Me, is greater than all; and no one is able to snatch them out of the Father's hand.
2 Corinthians 1:22 teaches that God has sealed the Christian and given us His Spirit in our hearts as a pledge.
In the Bible a seal is a sign of authenticity. If someone wanted to prove something was real, he would put a seal on it. A seal was also used to signify a completed transaction. When someone sold a plot of land, a seal confirmed the agreement between the buyer and the seller (e.g., Jer. 32:7-15). Most birth certificates issued have an embossed state seal on them to prove they are real.
Scripture also refers to a seal as a sign of authority. When someone acted as a representative for a king, he would carry the king's seal with him. That proved he represented the king's authority.
Scripture mostly uses the seal as a sign of security. When the Bible says we are “sealed with the Spirit,” that means we are secure.
The best Old Testament illustration of that appears in Daniel 6: "The king commanded, and they brought Daniel, and cast him into the den of lions. Now the king spoke and said unto Daniel, Your God, whom you serve continually, He will deliver you. And a stone was brought, and laid upon the mouth of the den; and the king sealed it with his own signet, and with the signet of his lords, that the purpose might not be changed concerning Daniel" (vv. 16-17).
When you are sealed with the Spirit, that means God's purpose in salvation can never be changed. The seal of our security is the Holy Spirit Himself, who assures us by His ongoing intercessory work. That is why in Ephesians 1:13 He is called the "Holy Spirit of promise. "