It is possible to know beyond a shadow of doubt that you are saved and will be in heaven some day.
Can a believer in the Lord Jesus Christ know with complete confidence that his salvation is perfect and eternal? Can he be sure that his sins are gone, that his name is written in heaven in the Lamb's book of life, that nothing can ever sever his relationship with God as Father, and that he is sure of glory? If it is possible to know these things without doubt, how may we know them and be sure of them?
God's Word teaches that it is not only possible to know these things, but also that God desires His children to know them and to rejoice in their certainty. The Word teaches us, moreover, that to know these things will make our Christian experience more joyful and more effectual; and it also teaches us that failure to know and believe these things dishonors God.
Paul writes thus to the Thessalonian believers, whom he had led to the Lord: "For our Gospel came not unto you in word only, but also in power, and in the Holy Ghost and in much assurance" (I Thess. 1:5). He prays for the Colossians "that their hearts might be comforted, being knit together in love, and unto all riches of the full assurance of understanding, to the acknowledgement of the mystery of God, and of the Father, and of Christ" (Col. 2:2); and the author of the Epistle to the Hebrews writes: "And we desire that every one of you do show the same diligence to the full assurance of hope unto the end" (Heb. 6:11), and, "Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water" (Heb. 10:22).
What is assurance? It is to know that we are saved and safe eternally. It is not to hope that we are saved; it is not to pray that we shall at last be saved; it is to know that we are here and now saved by God's grace, apart from any supposed merit on our side, or any present or future faithfulness on our part. It is to be able to say heartily with Paul: "For I know whom I have believed, and am persuaded that He is able to keep that which I have committed unto Him against that day" (II Tim. 1:12). "Being confident of this very thing, that He which hath begun a good work in you will perform it until the day of Jesus Christ" (Phil. 1:6).
It is to be feared, however, that a large number of true believers in the Lord Jesus Christ as Saviour do not have this assurance. Many, for example, believe that the Lord's keeping power depends upon their own faithfulness to the Lord. Such a view makes salvation to be the result of human merit rather than God's grace, and plainly contradicts such statements of Scripture as Eph. 2:8, 9: "For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: not of works, lest any man should boast."
Others feel that to be confident and sure that one is saved eternally, whatever may come, is to be presumptuous. The fact is, however, that for a true believer not to know that his salvation is eternal and perfect is to dishonor God, and also to make Him a liar by failing to believe the witness which He has given concerning His Son and His work on the cross. "He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made Him a liar; because he believeth not the record that God gave of His Son. And this is the record, that God hath given to us eternal life, and this life is in His Son. He that hath the Son hath life; and he that hath not the Son of God hath not life. These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God" (I John 5:10-13).
How may we know that we have eternal life? Upon what is such assurance based? It is not by any merely human feeling or emotion that we may have. It does not come by any visions, either real or imagined. Nor is it by some particular fantastic experience. It is simply by believing God's Word. It is to believe "the record that God gave of His Son." That record is, "how that Christ died for our sins according to the Scriptures; and that He was buried, and that He rose again the third day according to the Scriptures (I Cor. 15:3, 4). This is the Gospel, the message which came to the Thessalonians "in power, and in the Holy Ghost, and in much assurance" (I Thess. 1:5).
Assurance comes, we repeat, simply by taking God at His Word. He has promised that those who trust His Son are saved for time and eternity. We read: "For God so loved the world, that He gave His only begotten Son, that whosoever believeth in Him should not perish, but have everlasting life" (John 3:16). This verse assures me (for I am included in that blessed "whosoever") that if I believed in God's Son, whom He gave to die for my sins, I shall "not perish." I shall never again be exposed to that danger of eternal separation from God but I "have everlasting life," which means that God will keep me for time and eternity. God's Word, then, is the one and only basis of assurance and confidence. It is true that "the Spirit [Himself] beareth witness with our spirit, that we are the children of God" (Rom. 8:16), and it is through the Word that the Spirit bears this witness.
When we received Christ as our Saviour, it was "the acknowledging of the truth which is after godliness; in hope of eternal life, which God, Who cannot lie, promised before the world began" (Tit. 1:1, 2). Since God has promised "that whosoever believeth in Him should not perish, but have everlasting life," and since God "cannot lie," assurance to our hearts and honor to God alike come simply from believing His Word. Such faith delights the Father, as did the faith of Abraham who "was strong in faith, giving glory to God; and being fully persuaded that, what He had promised, He was able also to perform" (Rom. 4:20, 21).
Notice these encouraging and assuring promises of the Word, upon which we may safely and confidently base our assurance and by which we may know that we are saved by simple faith in God's dear Son: "He that believeth on Him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God" (John 3:18); "He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him" (John 3:36). The Lord Jesus said: "Verily, verily, I say unto you, He that believeth on Me hath everlasting life", (John 6:47). He also said: "Verily, verily, I say unto you, He that heareth My Word, and believeth on Him that sent Me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life" (John 5:24); and, "I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of My hand. My Father, which gave them Me, is greater than all; and no man is able to pluck them out of My Father's hand" (John 10:28, 29).
To be sure, there are certain evidences of salvation, which will be manifested in our lives. For example, "we know that we have passed from death unto life, because we love the brethren. He that loveth not his brother abideth in death" (I John 3:14). On the other hand, we know these evidences because they are given us in the Word of God, so that, basically, assurance is based entirely upon the Scriptures, and their veracity. The Pilgrim Bible says (page 1599, footnote 9): "ASSURANCE. This word speaks of the Christian's joyous faith because of his fearless trust in God and His sure Word…Assurance is our understanding that our souls are freed from the power of evil and from the judgment upon evil through Christ's finished work. It is not self- confidence; it is confidence in Christ."
What then causes the lack of assurance on the part of many of God's children? There are two primary reasons, we believe. First, ignorance of God's Word. Since, as we have seen, assurance comes from a knowledge of and trust in the truths revealed about Christ in the Word, not to know the Word means not to have assurance. There are doubtless those who have seen themselves as sinners, and have trusted Christ as Saviour; but they have not been fed upon the Word after being saved. Therefore they lack that glad and joyous assurance which God wants us to have, and which honors Christ.
Secondly, unjudged and unconfessed sin in a Christian's life will dim his assurance. "Add to your faith virtue; and to virtue knowledge; and to knowledge temperance; and to temperance patience; and to patience godliness; and to godliness brotherly kindness; and to brotherly kindness charity. For if these things be in you, and abound, they make you that ye shall neither be barren nor unfruitful in the knowledge of our Lord Jesus Christ. But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins" (II Pet. 1:5-9). "But whoso keepeth His Word, in him verily is the love of God perfected: hereby know we that we are in Him" (I John 2:5). "If ye will not believe, surely ye shall not be established" (Isa. 7:9).
We may have assurance, not only of eternal life itself but that the Lord is with us at all times, regardless of our feelings and circumstances, "for He hath said, I will never leave thee, nor forsake thee. So that we may boldly say, The Lord is my Helper, and I will not fear what man shall do unto me" (Heb. 13:5, 6).
We have assurance also that all that concerns us is His concern and that He, by His omnipotent power, is working all for His glory and our blessing: "And we know that all things work together for good to them that love God, to them who are the called according to His purpose. For whom He did foreknow, He also did predestinate to be conformed to the image of His Son, that He might be the Firstborn among many brethren...What shall we then say to these things? If God be for us, who can be against us?" (Rom. 8:28, 29, 31).
When we come to God in prayer, through our Lord Jesus Christ, we may come in assurance. "Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water" (Heb. 10:22). "And this is the confidence that we have in Him, that, if we ask anything according to His will, He heareth us: and if we know that He hear us, whatsoever we ask, we know that we have the petitions that we desired of Him" (I John 5:14, 15).
Lastly, we have the assurance of reward for our labors for the Lord, many of which are unappreciated and even reproached now. "Therefore, my beloved brethren, be ye stedfast, unmovable, always abounding in the work of the Lord, forasmuch as ye know that your labor is not in vain in the Lord" (I Cor. 15:58).
So, we have assurance by simple belief in the Gospel (I Thess. 1:5); our hearts are comforted as we enter into "all riches of the full assurance of understanding" (Col. 2:2); this assurance, instead of making us careless and neglectful, produces diligence in us (Heb 6:11); and we may, with confidence, bring all our problems and needs to Him "in full assurance of faith" (Heb. 10:22).
"Who shall separate us from the love of Christ? Shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword? As it is written, For Thy sake we are killed all the day long; we are accounted as sheep for the slaughter. Nay, in all these things we are more than conquerors through Him that loved us. For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come, nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord" (Rom. 8:35-39).
From Great Doctrines Relating to Salvation by John B. Marchbanks. Neptune, NJ: Loizeaux Brothers, 1970. Chapter 7.