Many Christians who are members of Bible-preaching, evangelical churches have been duped somehow into thinking that their perseverance in the faith is dependent on their own natural abilities to endure to the end. They have become practical deists, thinking that after God make us a new creation (2 Corinthians 5:17) he simply left us to our own devices while he just sits back observing us through life’s difficulties, waiting to see if we will make it to the end.
   In his first wartime address, delivered at Guildhall in London on September 4, 1914, Sir Winston Churchill (1874-1965) said: “Sure I am of this, that you have only to endure to conquer. You have only to persevere to save yourselves.” Considering what Churchill accomplished during his life, he proved this statement to be entirely appropriate. The British Prime Minister’s wartime victories demonstrated time and again his ability to persevere to the end he overcame great odds, and his self-sustained resilience enabled him to endure all the struggles of leadership during the Second World War. And while his assertion is accurate, it is accurate only insofar as it pertains to our natural human abilities. Churchill’s call to persevere in order to save oneself is by all means applicable to soldiers in wartime. It is a stern charge to fight to the end in order to overcome the enemy. Moreover, It conveys a similar exhortation found in the Bible. In Hebrews, we are called to run the race set before us (12:1). The apostle Paul likewise admonishes us to endure so that we might “reign with [Christ]” (2 Timothy2:12). And while teaching his disciples, Christ himself said: “The one who endures to the end will be saved” (Matthew 10:22). In these passages and others, the Bible’s teaching is clear; we must persevere to the end in order to be saved. However, this is only one part of the biblical equation. If our perseverance in the faith is dependent upon us, we will surely fail and will by no means finish the race set before us. Moreover, our assurance of salvation will waver each and every day if we are counting on ourselves and our own natural abilities to persevere to the end (Romans 4:20; Hebrews 10:23). In order to have full assurance, we must be entirely dependent upon Christ and his Word, which he has provided for us as our only infallible rule to faith and life (Westminster Confession of Faith 1.2). In his letter to the Colossians, the apostle Paul writes to the saints and faithful believers in Christ at Colossae:

For I want you to know how great a struggle I have for you and for those at Laodicea and for all who have not seen me face to face, that their hearts may be encouraged, being knit together in love, to reach all the riches of full assurance of understanding and the knowledge of God’s mystery, which is Christ, in whom are hidden all the treasures of wisdom and knowledge. (Colossians 2:1-3)

—Burk Parsons, Assured by God (P&R 2006), 20–21.

Much of the reason that Christians lack full assurance of their salvation is because they do not possess a right understanding of the purpose of salvation. Most Christians think their salvation is first and foremost about them. When I begin premarital counseling with a couple in our church, one of the first things we talk about is the purpose of marriage. I usually astonish the couple when I tell them that their marriage is not about them. After the initial shock, the young man and woman usually just look at me with blank stares. I then go on to explain that marriage is first and foremost about God and his kingdom (Ephesians 5:30&ndash32). We spend some time talking about the creation ordinance to be fruitful and multiply, and, considering the possibility that the couple may not have children in the future, I explain that their marriage is intended to bring glory to God as each fulfills his or her covenant role in the relationship. I explain that they are getting married not just to live under the same roof with the same last name, but that their relationship is to reflect the relationship between Christ and his bride (5:25–29). When the couple understands that, they have a solid foundation on which to build a loving and full marriage.

—Burk Parsons, Assured by God (P&R 2006), 26.