Conditional or Unconditional Assurance?

I find reading the Apostle John's letters especially beneficial for the simple reason that they are non-Pauline; they allow for a contrast, a reading of a different tenor or tone. John opens his first epistle by explaining that he preaches the word which he had seen and which was "made manifest" to him (1 John 1:2). He shares what he saw so that his audience might have "fellowship" with him, who is himself in fellowship "with the Father and with his Son Jesus Christ." (v. 3.)

To have fellowship with one another, an ambition that is (in my finer moments) quite dear to me, we must walk in the light, which is Christ. And in that case, the blood of Christ "cleanses us from all sin." (v. 7.) This serves as a preface for the beginning of 1 John 2, a recent liturgical reading. John says that "we may be sure that we know him" by "keep[ing] his commandments." (1 John 2:3.) This is reminiscent of John's own Gospel, in which he records the words of Christ, that "If you love me, you will keep my commandments." (John 14:15.)

Is the keeping of Christ's commandments a required step to validate and vest one's claimed love for Christ, or is it mere evidence of election? In other words, from John's letter does it appear that obedience is a sign of or an agent in achieving unity with Christ's propitiatory work? Is there a condition or not?

1 John 2 reads as if there may still be a condition. "He who says 'I know him' but disobeys his commandments is a liar, and the truth is not in him; but whoever keeps his word, in him truly love for God is perfected. By this we may be sure that we are in him: he who says he abides in him ought to talk in the same way in which he [Christ] walked." (1 John 2:5-6). The disobedience doesn't seem to undo (on its own) one's possession of truth, but rather to evidence that the person is "a liar." But on the other hand, some action really flows from the keeping of commandments -- it is not mere assurance, mere evidence of prior election. In whoever keeps Christ's word, truly love for God is perfected. (As a matter of interpretation, this has to differ from a text that would say, "already perfect love is made known.")

It could be that, upon appreciating our having received the grace to obey divine commandments, we both find assurance in what has been done, and cooperate in the perfection of this love. If this is objectionable, I suspect the objection arises from a predisposition to a monocausalistic view.