“But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins.”
2 Peter 1:9

He also said:
“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.” 2 Peter 1:8
As much as it is clear that the man who doesn’t add to his faith moral excellence and knowledge would most likely go on walking in his old sins and would live his life as a blind man who’s short sighted (no consciousness of his eternal relevance or place in Christ) he also shows us that adding the things mentioned to our faith in abounding measure would cause us to be productive and effective in the knowledge of our Lord Jesus Christ.
This means knowing and learning about Jesus would become exciting and worthwhile; we would become active in our knowledge of him and not just lazying about and unproductive (even though we might have nice sounding words). Philemon 1:6.
Always seek to walk in moral goodness, purity and be diligent in increasing your knowledge of the Lord.