Christ as a Son over His own house, whose house we are if we hold fast the confidence and the rejoicing of the hope firm to the end. Hebrews 3:6

This verse provides crucial instructions on how to be considered one of the saints that perseveres to the end. You take part in persevering by a maintaining a fearless confession and joyful hope in what is unseen, holding fast unto your faith with full assurance that God won't let go. God never promises that perseverance will come easy, it is a fight and a struggle, but you must remember that the victory has already been won by Christ. All that is left for us to do is to hold fast to Him who we believe because in Him we find our strength.

Persevering to the end is only possible by the grace of God, but it does not happen without you holding fast to the cross. Let your desire to persevere be fueled by the promises of God's Word. He will never leave you nor forsake, there is no way to sin past the grips of His love. The work of grace that He has started He will be faithful to complete, His completion of the work will be because of your faithfulness and not your merit. If he has given you eternal life then you have no need to fear because you cannot perish and His grip is firmly on you and none can snatch you from His hand.

Your key task is to work out your salvation with fear and trembling to verify that you are indeed in God's grip. There are many who initially claim Christ, but don't hold fast. Instead of believing, they gradually drift into unbelief about God's faithfulness and promises. The sin of unbelief rarely happens in a big leap, but it is always the result of a steady inching away from truth to lies and self-sufficiency. Fight the lies with confessing the gospel and self sufficiency with rejoicing in the hope founded on the truth that salvation is not dependent of yourself. He is the author and perfect of your faith, so look to outwards and upwards where your grip is and see that He will never let go of you.