The assurance of Faith is based completely on your walk with God,

That statement is in error. If you were an Israelite attempting to stay in the promise land which had promises that were conditional you might could make a case, but we are not. Our assurance of salvation cannot be based on our walk, but only on Him. Our walk follows what Jesus has done in us.

based completely on your walk with God,

So you believe that God will judge you based on your walk and if you are good enough He will let you into heaven? This view denigrates the work and blood of Jesus.

Now dear reader, you, too, may be quite sure that your faith in Christ is true “gold,” and yet, after all, be mistaken. The human heart is dreadfully deceitful (Jer. 17:9). God’s Word plainly warns us that “There is a generation that are pure in their own eyes, and yet is not washed from their filthiness” (Prov. 30:12). Do you ask (O that you may, in deep earnestness and sincerity), How can I be sure that my faith is a genuine and saving one? The answer is, Test it. Make certain that it is the, “faith of God’s elect” (Titus 1:1). Ascertain whether or not your faith is accompanied with those fruits which are inseparable from a God-given and Spirit-wrought faith.

Probably many are ready to say, There is no need for me to be put to any such trouble; I know that my faith is a saving one, for I am resting on the finished work of Christ. But dear friend, it is foolish to talk like that. God Himself bids His people to make their “calling and election sure” (2 Peter 1:10). Is that a needless exhortation? O pit not your vain confidence against Divine wisdom. It is Satan who is striving so hard to keep many from this very task, lest they discover that their house is built on sand. There is hope for one who discovers his illusion, but there is none for those who go on believing the Devil’s lie, and rest content with the very real but false peace which he gives to so many of his poor victims.

God Himself has supplied us with tests, and we are mad if we do not avail ourselves of them, and honestly measure ourselves by them. “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 (more intelligently) on the name of the Son of God” (1 John 5:13). The Holy Spirit Himself moved one of His servants to write a whole Epistle to instruct as how we might know whether or not we have eternal life. Does that look as though the question may be determined and settled as easily as so many present-day preachers and writers represent it? If nothing more than a firm persuasion of the truth of John 3:16 or 5:24 be needed to assure me of my salvation, then why did God give a whole Epistle to instruct us on this subject?

Let the really concerned soul read slowly and thoughtfully through this first Epistle of John, and let him duly observe that not once in its five chapters are we told, “We know that we have passed from death unto life because we are resting on the finished work of Christ.” The total absence of such a statement ought, surely, to convince us that something must be radically wrong with so much of the popular teaching of the day on this subject. But not only is there no such declaration made in this Epistle, the very first passage which contains the familiar “we know” is quite the reverse of what is now being so widely advocated as the ground of Christian assurance. “And hereby we do know that we know Him, if we keep His commandments” (1 John 2:3). Is not that plain enough? A godly life is the first proof that I am a child of God.

But let us observe the solemn declaration that immediately follows. “He that saith, I know Him, and keepeth not His commandments, is a liar, and the truth is not in him” (1 John 2:4). Do these words anger you? We trust not: they are God’s, not ours. Do you refuse to read any more of this article? That would be a bad sign—an honest heart does not fear the light. A sincere soul is willing to be searched by the Truth. If you are unable to endure now the feeble probing of one of His servants, how will it fare in a soon-coming day when the Lord Himself shall search you through and through? O dear friend, give your poor soul a fair chance, be willing to ascertain whether your faith is real wheat, or only chaff. If it proves to be the latter, there is still time for you to humble yourself before God and cry unto Him to give you saving faith. But in that Day it will be too late!

“He that saith, I know Him, and keepeth not His commandments, is a liar, and the truth is not in him” (1 John 2:4). How plain and pointed is that language! How awful its clear intimation! Do you not see, dear reader, this verse plainly implies that there are those who claim to know Christ, and yet are liars? The father of lies has deceived them, and he is doing everything in his power to keep them from being undeceived. That is why the unregenerate reader finds this article so unpalatable, and wishes to turn from it. O resist this inclination, we beseech you. God has given us this very verse by which we may measure ourselves, and discover whether or not our “assurance of salvation” will stand the test of His Holy Word. Then act not like the silly ostrich, which buries his head in the sand, rather than face his danger.

Let us quote one more verse from this first “we know” passage in John’s Epistle: “But whoso keepeth His Word, in him verily is the love of God perfected: hereby know we that we are in Him” (1 John 2:5). This stands in sharp contrast from the preceding verse. The Apostle was here moved to set before us some clear Scriptural evidences of spiritual faith and love, within constitute the vital difference between sheep and goats. In verse 4 it is the empty professor who says, “I know Christ as my personal Saviour.” He has a theoretical, but not a vital knowledge of Him. He boasts that he is resting on Christ’s finished work, and is confident that he is saved: but keeps not His commandments. He is still a self-pleaser. Like Solomon’s sluggard, he is “wiser in his own conceits than seven men that can render a reason” (Prov. 26:16). He talks boldly, but walks carelessly.

In verse 5 it is the genuine Christian who is in view. He does not say, “I know Him,” instead, he proves it. The Apostle is not here presenting Christ as the immediate Object of faith, but is describing him who has savingly fled to the Lord for refuge, and this, by the effects produced. In him Christ’s Word is everything: his food, his constant meditation, his chart. He “keeps” it in memory, in heart, in action. Christ’s “commandments” occupy his thoughts and prayers as much as do His promises. That Word working in him subdues his carnal desires, feeds his graces, and draws them into real exercise and action. That Word has such a place in his heart and mind that he cannot but give proof of the same in his talk and walk. In this way the “love of God is perfected”: the Family likeness is plainly stamped upon him. All can see to which “father” he belongs—contrast John 8:44.

“Whoso keepeth His Word . . . hereby (in this way) know we that we are in Him.” Keep His Word perfectly? No. But actually, characteristically, in deep desire and honest effort to do so? Yes. Regeneration is that miracle of Divine grace wrought in the soul which enlists the affections Godwards—which brings the human will into subjection to the Divine—and which produces a real and radical change in the life. That change is from worldliness to godliness, from disobedience to obedience. At the new birth the love of God is shed abroad in the heart by the Holy Spirit, and that love is manifested in a dominating longing and sincere purpose to please in all things the One who has plucked me as a brand from the burning. There is a greater difference between the genuine Christian and the deceived professing Christian than there is between a living man and a corpse. None need remain in doubt if they will honestly measure themselves by the Holy Word of God.

There is only space left for us to consider one other Scripture in this opening article, namely, the Parable of the Sower. Why did the Lord Jesus give us that parable? Why, but to stir me up to serious inquiry and diligent examination so as to discover which kind of a “hearer” I am. In that parable, Christ likened those who hear the Word unto various sorts of ground upon which seeds fall. He divided them into four different classes. Three out of the four brought no fruit to perfection. That is exceedingly solemn and searching. In one case the Devil catches away the good seed out of the heart (Luke 8:12). In another case, they “for a while believe, and in time of temptation fall away” (Luke 8:13). In another case, they are “choked with cares and riches and pleasures of this life” (Luke 8:14). Are you, my reader, described in one of these? Do not ignore this question. We beg you: face it honestly, and make sure which of the various soils represent your heart.

But there are some “good ground” hearers. And how are they to be identified? What did the infallible Son of God say of them? How did He describe them? Did He say, “that on the good ground are they who rest on the Word of God and doubt not His promises: are thoroughly persuaded they are saved, and yet go on living the same kind of life as previously”? No. He did not. Instead, He declared, “But that on the good ground are they, which in an honest and good heart, having heard the Word, keep it, and bring forth fruit with patience” (Luke 8:15). Ah, dear readers, the test is fruit: not knowledge, not boasting, not orthodoxy, not joy, but FRUIT: and such “fruit” as mere nature cannot produce. It is the fruit of the Vine, namely, likeness to Christ, being conformed to His Image. May the Holy Spirit search each one of us.

There is a lot more to this article, if you'd like to read it @ http://spurgeongems.org/awp_assur.htm

http://www.gotquestions.org/erased-book-life.html explains it well. 

Many have no assurance because they have not grown to maturity.  I had no assurance for quite a while.  I still have thoughts at times, but I'm standing more firm on scripture each day as I stay in it.  And we're told that false believers will not remain in the vine. 

Look at John 15:1-4:  “I am the true vine, and my Father is sthe vinedresser. Every branch in me that does not bear fruit he takes away, and every branch that does bear fruit he prunes, that it may bear more fruit. Already you are clean because of the word that I have spoken to you.  Abide in me, and I in you. As the branch cannot bear fruit by itself, unless it abides in the vine, neither can you, unless you abide in me.

This is saying that we bear more fruit as we abide in Him.  So a recently saved person may not appear to bear much fruit, but if the fruit doesn't grow they may not be abiding in Christ or in the Word, remaining in the Word, and so He ultimately takes them away....or perhaps reveals the mask they've been hiding under.  The unbelievers who profess to be Christian.

I warred about my assurance because I couldn't tell that I was bearing fruit.  I was looking at the mature Christians who didn't react to those who hurt them terribly and I was not able to do that...those who didn't get irritated with people and I was still doing that...and so I thought I wasn't saved because I wasn't acting appropriately.  Yet others have commented on things they've seen grow in me, and it's come to a point that I can finally recognize these things.  It's a process we all go through. 

I warred with eternal salvation as well until I'd read and studied scripture enough that I could see that those who do not remain are those who are the unbelievers professing Christ.  They are among us but not of us.  I had to come to the realization that it is "true repentance" that is the key.  Not everyone who says they've repented truly have.  They are like dogs who return to their own vomit eventually.