“Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall:”
2 Peter 1:10

“…and to patience godliness;” 2 Peter 1:6
Be godly; be a pious person; live that sanctified life.
The word of God is our sanctification, Jesus said:
“Sanctify them through thy truth: thy word is truth.” John 17:17
This means we submit ourselves to the word and our expressions become the expressions of the word of God, the kind of company we keep is defined by God’s word:
“Blessed is the man that walketh not in the counsel of the ungodly, nor standeth in the way of sinners, nor sitteth in the seat of the scornful.” Psalms 1:1
The thoughts we allow in our mind are sanctified by the word of God:
“Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.” Philippians 4:8
The words we speak are an expression of God’s word:
“Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers.” Ephesians 4:29
He says abound in piety, the person who does not:
“…cannot see afar off, and hath forgotten that he was purged from his old sins.” 2 Peter 1:9
But you were purged from your old sins and so act accordingly, live a life of consecration- when you do, you will never fall.