Okay,
@zoidar so we have to look at the full context of the verse. Firstly, he's speaking to the churches in Asia minor, and he's speaking in the context of staying steadfast in the faith brought them by Apostles...
2 that you may be mindful of the words which were spoken before by the holy prophets, and of the commandment of us, the apostles of the Lord and Savior, 3 knowing this first: that scoffers will come in the last days, walking according to their own lusts, 4 and saying, “Where is the promise of His coming? For since the fathers fell asleep, all things continue as they were from the beginning of creation.”
Here there is specific warning, scoffers will come and try to lead them astray concerning the Lords second coming, telling them not to fall for the deception. The LORD will come, time is not a factor. He will always fulfill His promises in His own time. He continues:
Therefore, since all these things will be dissolved, what manner of persons ought you to be in holy conduct and godliness, 12 looking for and hastening the coming of the day of God
Here we see admonition to good conduct as a result which continues:
Therefore, beloved, looking forward to these things, be diligent to be found by Him in peace, without spot and blameless; 15 and consider that the longsuffering of our Lord is salvation—
And:
beware lest you also fall from your own steadfastness, being led away with the error of the wicked; 18 but grow in the grace and knowledge of our Lord and Savior Jesus Christ.
So the admonition to repentance can simply be speaking of the same type of mindset, as we continually need to be moving toward ever greater repentance, turning more and more away from self and more and more into an ever deepening relationship with our Lord...
I see repentance as ongoing toward a more perfect or more perfected walk in Christ.