For this very reason, make every effort to add to your faith goodness; and to goodness, knowledge; and to knowledge, self-control; and to self-control, perseverance; and to perseverance, godliness; and to godliness, brotherly kindness; and to brotherly kindness, love. For if you possess these qualities in increasing measure, they will keep you from being ineffective and unproductive in your knowledge of our Lord Jesus Christ. But if anyone does not have them, he is nearsighted and blind, and has forgotten that he has been cleansed from his past sins. Therefore, my brothers, be all the more eager to make your calling and election sure. For if you do these things, you will never fall, and you will receive a rich welcome into the eternal kingdom of our Lord and Savior Jesus Christ. II Peter 1:5-11
Perseverance means sticking with it even though it might be hard. The path gets narrow as those who are struggling give up. Do not give up, because it is hard to get started again. Just keep swimming!