Summary: The believer in Christ, through the instruction from God's word and the direction of the Holy Spirit can be confident in his salvation and equipped in his walk with God through this world.
1.) The Believer Can Know He Has Eternal Life 1Jn_5:13-15
A. Security in Jesus v.13
John writes that those who have put their faith in Jesus Christ can Know that they have eternal life and have their faith increased by this knowledge.
ETER'NAL, a. 1. Without beginning or end of existence. 2. Without beginning of existence. 3. Without end of existence or duration; everlasting; endless; immortal. 4. Perpetual; ceaseless; continued without intermission. 5. Unchangeable; existing at all times without change; as eternal truth.
God cannot lie thus his word is true and so we can have certainty He means what he says when he says "eternal".
Deu_32:4 He is the Rock, his work is perfect: for all his ways are judgment: a God of truth and without iniquity, just and right is he.
Temptation is hard to resist in this mortal body, there is a constant battle inside of a believer living in this present world, and it is easy to doubt ourselves and our motives but we should never doubt the motives and promises that come from God.
Gal_5:17 For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would.
When a person truly calls on the Lord to be saved, they are saved from that moment on. We must remember though, God never promised to save our flesh, but he did say he would save our soul, for which he gives "the earnest of the Spirit" (2Co_1:22) and in which he promised to redeem at the time of his return.
EARNEST, n. ern'est. Seriousness; a reality; a real event; as opposed to jesting or feigned appearance. 1. First fruits; that which is in advance, and gives promise of something to come. Early fruit may be an earnest of fruit to follow. The first success in arms may be an earnest of future success. The Christian’s peace of mind in this life is an earnest of future peace and happiness. Hence earnest or earnest-money is a first payment or deposit giving promise or assurance of full payment. Hence the practice of giving an earnest to ratify a bargain.
Also Eph_4:30; Eph_1:13
B. Assurance in prayer v.14-15
When a person receives new life in Christ there is a line of communication that is opened with God himself.
The Holy Spirit knows our heart and helps a believer know the will of God and how to get closer to him, and when we can't form the words to express what we want to say the Holy Spirit will speak on our behalf.
Rom_8:26-27 Likewise the Spirit also helpeth our infirmities: for we know not what we should pray for as we ought: but the Spirit itself maketh intercession for us with groanings which cannot be uttered. (27) And he that searcheth the hearts knoweth what is the mind of the Spirit, because he maketh intercession for the saints according to the will of God.
The closer we get to God and the deeper we get into his word the more our prayers match his will, and when that happens God not only hears our prayers but will answer them every time.
Joh_15:7 If ye abide in me, and my words abide in you, ye shall ask what ye will, and it shall be done unto you.
2.) The Believer Can Know He Has Forgiveness 1Jn_5:16-19
A. Intercessory prayer for the brethren v.16-17
All sin can be forgiven after salvation, as a child of God we should have the compassion and care to intercede in prayer on the behalf of our brothers and sisters in Christ when we see them in the midst of sinful behavior.
We must always pray for the conviction of the lost and be witnesses of the Gospel, but understand that one who is in a state of rebellion against God and denies Jesus cannot be forgiven of that sin. They must come to their self and put their faith and trust in him to receive forgiveness.
Mat_12:31 Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men.
B. The promise of forgiveness v.18-19
The sin nature is in the flesh and God saves the believers soul not his flesh. God seals the believers soul at the time of salvation with the Holy Spirit at which point the believers spirit receives new life, and this new spirit cannot sin. This also prevents the devil from corrupting it.
Eph_1:13 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,