While we often admire those who have faithfully walked with Christ, we often forget we are on the same journey. The idea of faithful, consistent Christianity has almost altogether left our collective conscience in our modern age of distraction. However, this destination the old and faithful saints arrive at must be desired and lauded by all Christians, for it takes much patience and perseverance to achieve. It is, indeed, a supernatural achievement.
What does it take to reach this destination?
Certainly, it is not idly waiting for old age to arrive. That cannot create a faithful saint. Faithful saints are forged over time in fiery trials and desolation, experiencing the blessings of God through it all. One thing holds them up, encouraging them onward—the promises of God. Faithful saints are faithful because they intimately know the faithfulness of God.
Reaching this destination cannot come through good intentions, either. A person may intend well but act in such a way that hinders them from reaching their goal. In one of Jesus’ illustrations, a father asks his sons to work in the vineyard. The first tells his father he won’t do it, but later does it; the second tells his father he will do it but doesn’t. The moral of the parable is that the well-intentioned son acted in such a way that did not please his father (Matthew 21:28-32).
Likewise, many Christians have great intentions of being faithful to God into old age, but never make it because they spent their Christian life depending on themselves. This path usually has them spending most of their time in the muck and mire, sorry for their state in life, or set on a constant diet of excitement to distract themselves from reality. Either way, they miss the pathway of a faithful saint. To be a faithful Christian, you must take a roundabout way.
I say this not as one who has travelled this pathway to the end, but as an observer of those who have gone before me. There seems to be a common thread, and that thread consists wholly of standing on the promises of God for a very long time.
Caleb and Joshua are two examples of faithful saints. God had promised the land of Canaan to Israel as their inheritance. As the twelve men returned to Israel’s camp from spying out the Promised Land, these two trusted God to keep His promise despite the visibly insurmountable obstacles in their way. As the story goes, Israel was forced to wander in the desert until that unbelieving generation died. Only then could they enter the land of Canaan. This meant Caleb and Joshua had to stand on a single promise for forty years.
Their trust in God was caused by their knowledge of God. In 1 John, the apostle writes,
"I am writing to you, little children, because your sins have been forgiven you for His name’s sake. I am writing to you, fathers, because you know Him who has been from the beginning. I am writing to you, young men, because you have overcome the evil one. I have written to you, children, because you know the Father. I have written to you, fathers, because you know Him who has been from the beginning. I have written to you, young men, because you are strong, and the word of God abides in you, and you have overcome the evil one" (1 John 2:12-14).
John twice describes the mature in faith as fathers who “know Him who has been from the beginning.” Contrasted with the immature in faith who simply know the Father, the mature has a deep, tested knowledge of God. Caleb and Joshua didn’t know God in a simple way; they knew God well. They understood that God was eternal and unchanging.
Christians who are not acquainted with God's attributes of eternality and immutability are at a disadvantage. Like a child, unable to understand why the world is the way it is, grows frustrated when things don’t happen the way they wish, so these Christians grow frustrated at God for allowing trials and hardships. God is eternal and unchangeable (immutable), making His Word eternal and unchangeable. This is the foundation of God’s faithfulness. When Christians understand these attributes of God, they are not easily frustrated in their thoughts of God, nor of this world, for they know that although life in this world always changes, God never changes.
Standing on the promises that cannot fail, when the howling storms of doubt and fear assail, by the living Word of God I shall prevail, standing on the promises of God.
To be a faithful saint, you must stand on the promises of God for a very long time. To stand on the promises for a long time, you must know and treasure the attributes of God’s eternality and immutability.
 Russel K. Carter, “Standing on the Promises of Christ my King”