In a previous post, I pointed out that Christlikeness is something that awaits us in the future, namely, glorification, i.e., having our bodies transformed to be like Jesus Christ’s glorified body. And we have to pursue this goal primarily in terms of remaining faithful to the end.
Romans 8:29-30 ESV
For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers.  And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified.
Philippians 3:10-14 ESV
that I may know him and the power of his resurrection, and may share his sufferings, becoming like him in his death,  that by any means possible I may attain the resurrection from the dead.  Not that I have already obtained this or am already perfect, but I press on to make it my own, because Christ Jesus has made me his own.  Brothers, I do not consider that I have made it my own. But one thing I do: forgetting what lies behind and straining forward to what lies ahead,  I press on toward the goal for the prize of the upward call of God in Christ Jesus.
Colossians 1:21-23 ESV
And you, who once were alienated and hostile in mind, doing evil deeds,  he has now reconciled in his body of flesh by his death, in order to present you holy and blameless and above reproach before him,  if indeed you continue in the faith, stable and steadfast, not shifting from the hope of the gospel that you heard, which has been proclaimed in all creation under heaven, and of which I, Paul, became a minister.
But what about Christlikeness in the present? Yes, we also pursue Christlikeness in the present in terms of being gradually conformed to his moral image, his holy character.
1 John 3:2-3 ESV
Beloved, we are God’s children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is.  And everyone who thus hopes in him purifies himself as he is pure.
2 Corinthians 3:17-18 ESV
Now the Lord is the Spirit, and where the Spirit of the Lord is, there is freedom.  And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another. For this comes from the Lord who is the Spirit.
Pursuing the Christlikeness that awaits us in the future (i.e., attaining the resurrection from the dead) in terms of persevering to the end, and pursuing Christlikeness in the present by purifying ourselves and constantly contemplating Christ’s glory in Scripture so that the Spirit can imprint Christ’s image on our souls, are interrelated. By pursuing Christlikeness in the present, we ensure that we attain Christlikeness in the future.
What is actually happening is: God is making us holy to make sure that we see him (in the person of his Son) on the day Christ returns and thus be transformed into Christ’s image. This is what Hebrews 12:14 means in relation to 1 John 3:2.
Hebrews 12:14 ESV
Strive for peace with everyone, and for the holiness without which no one will see the Lord.
But it may be asked, Why is all this necessary? Aren’t we already justified by faith alone and therefore we will no longer be condemned and are sure to be glorified (Rom. 8:1, 30)?
To answer that I have to use this analogy: A son might indeed be the heir to his father’s business empire. There is no doubt that someday he will inherit it. Still he must be made ready for it. Therefore, his father will teach him, develop him, guide him, and even discipline him, to make sure that he’ll be fit to manage the family business when he takes over someday.
In the same way, we may have even now title to heaven, but we are not yet morally fit to enter and enjoy it. (Also, it seems from certain passages in Scripture that we will have responsibilities in the life to come that we must be made ready for.) That is why God goes through all the trouble of sanctifying us now (this includes his fatherly discipline) before he glorifies us. He is trying to bring us to a state where our sanctification matches our justification (see Hebrews 10:14). And he will complete this process (Philippians 1:6). I read somewhere that a justified person who is at the same time unsanctified is an impossible combination. Those whom God justified will not fail to be glorified. This implies that they will also be sanctified. (See Romans 8:30).