The faithfulness of God is the foundation of our hope of final perseverance. Christians shall persevere in holiness, because God perseveres in grace. Charles H. Spurgeon writes:
I give thanks to my God always for you because of the grace of God that was given you in Christ Jesus, that in every way you were enriched in him in all speech and all knowledge—even as the testimony about Christ was confirmed among you—so that you are not lacking in any gift, as you wait for the revealing of our Lord Jesus Christ, who will sustain you to the end, guiltless in the day of our Lord Jesus Christ. God is faithful, by whom you were called into the fellowship of his Son, Jesus Christ our Lord. (1 Corinthians 1:4-9 ESV)
Friend just beginning in the divine life, the Lord can give you an irreproachable character. Even though in your past life you may have gone far into sin, the Lord can altogether deliver you from the power of former habits, and make you an example of virtue. He can not only make you moral, but He can make you abhor every false way and follow after all that is saintly. Do not doubt it. The chief of sinners need not be a whit behind the purest of the saints. Believe for this, and according to your faith shall it be unto you. Oh, what a joy it will be to be found blameless in the day of judgement! We sing not amiss, when we join in that charming hymn:
Bold shall I stand in that great day,
For who aught to my charge shall lay;
While through Thy blood absolved I am,
From sin’s tremendous curse and shame?
What bliss it will be to enjoy that dauntless courage, when heaven and earth shall flee away from the face of the Judge of all! This bliss shall be the portion of everyone who looks alone to the grace of God in Christ Jesus, and in that sacred might wages continual war with all sin.
The hope which filled the heart of Paul concerning the Corinthian brethren we have already seen to be full of comfort to those who trembled as to their future. But why was it that he believed that the brethren would be confirmed unto the end? I want you to notice that he gives his reasons. Here they are:
God is faithful, by whom you were called into the fellowship of his Son, Jesus Christ our Lord. (1 Corinthians 1:4-9 ESV)
The apostle does not say, “You are faithful.” Alas! the faithfulness of man is a very unreliable affair; it is mere vanity. He does not say, “You have faithful ministers to lead and guide you, and therefore I trust you will be safe.” Oh, no! if we are kept by men we shall be but ill kept. He puts it, “God is faithful.” If we are found faithful, it will be because God is faithful. On the faithfulness of our covenant God the whole burden of our salvation must rest. On this glorious attribute of God the matter hinges. (All of Grace)