Jesus said: ‘Truly I tell you, unless you change and become like children, you will never enter the kingdom of heaven.’ (Matthew 18:3)
‘These words of our Lord refer to our initial conversion, but we should continue to turn to God as children, being continuously converted every day of our lives. If we trust in our own abilities, instead of God’s, we produce consequences for which God will hold us responsible. When God through His sovereignty brings us into new situations, we should immediately make sure that our natural life submits to the spiritual, obeying the orders of the Spirit of God. Just because we have responded properly in the past is no guarantee that we will do so again. The response of the natural to the spiritual should be continuous conversion, but this is where we so often refuse to be obedient. No matter what our situation is, the Spirit of God remains unchanged and His salvation unaltered. But we must “put on the new man…” (Eph 4:24). God holds us accountable every time we refuse to convert ourselves, and He sees our refusal as wilful disobedience. Our natural life must not rule— God must rule in us.
To refuse to be continuously converted puts a stumbling block in the growth of our spiritual life. There are areas of self-will in our lives where our pride pours contempt on the throne of God and says, “I won’t submit.” We deify our independence and self-will and call them by the wrong name. What God sees as stubborn weakness, we call strength. There are whole areas of our lives that have not yet been brought into submission, and this can only be done by this continuous conversion. Slowly but surely we can claim the whole territory for the Spirit of God.’
(from My Utmost for His Highest by Oswald Chambers, an early twentieth-century Scottish Baptist and Holiness Movement evangelist and teacher)