You cannot be a believer in Christ Jesus unless the word of God is the standard of truth in your life. If there is any wavering about this in your mind, then you have given the enemy a huge advantage to snuff out your spiritual life. The word of God is the actual sustenance our spirits need in order to grow and mature in the faith (Hebrews 5:12).
Many professing Christians are actually not believers at all. Rather, they are beleavers. I call them beleavers because they 'be leaving' the Lord at the drop of a hat. They have not committed to give their life to Jesus. They are not willing to stand with Him against that which is evil. They use Jesus like window dressing to pretty up the outward appearance of their lives, but leave the doctrine of Christ and deny Him at the slightest sign of pressure or conflict.
beleave: to cause or allow to remain behind, to leave something behind; to abandonA lot of time is wasted talking to and trying to reason with beleavers. They spend most of their time disputing the word of God and explaining why it does not mean what it says...and then they'll get mad at you when you point them to the Scriptures.
"They profess that they know God; but in works they deny him, being abominable, and disobedient, and unto every good work reprobate." Titus 1:16
Someone recently contacted me, disturbed because a number of what they had considered strong Christians seem to be gravitating closer to the world and farther away from God. To hold on to a religious facade, these persons are taking refuge in false doctrines such as Once Saved Always Saved or Universalism which says God's love will save everybody in the end. They will believe anything in order to continue pretending that their sin has no bearing on their eternal relationship with God.
Although this person sought reassurance, all I could say is, "It is written." God warns us in His word that a great falling away will occur prior to His return. This is the time to see it. If our hearts are not wholly set on the truths of God - if there is any part of us that still longs to do things our own way - then we may very well be in danger of falling into apostasy. When the rubber meets the road and it is truly time to chose whom we will serve, the beleaver is going to run for the hills for they have no anchor or root in their souls.
The issue is not that beleavers don't understand what God says. The problem is that there's still sin in the camp. They are willfully continuing in sin in some area of their lives and they do not want to give it up. They don't want to repent (which means to turn away from sin). Don't be shaken up as you see this begin to happen around you. Just make sure that you are keeping your body under subjection so as not to become a castaway yourself (I Corinthians 9:27).
You may very well find that those most receptive to the Gospel these days are not the professing beleavers, but those who have been outside of the religious domain. This is just as it was in Jesus' days. The religious sinners saw no need for repentance, but those who were broken and humble before the Lord came to Him in droves.
"Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye double minded." James 1:8
The only issue between man and God is sin. It is not that we don't know God loves us. It is not that we need tangible proof God exists. It is not that we pride ourselves on being a 'freethinker'. There is only one reason that people do not give their lives to the Lord, and that is they love the darkness of lies more than they love the light of truth (John 3:19).
"Think not that I am come to send peace on earth: I came not to send peace, but a sword. For I am come to set a man at variance against his father, and the daughter against her mother, and the daughter in law against her mother in law." Matthew 10:34-35
God wants to know; who is on His side? Will faith be found on the earth when He returns? Don't get distracted by the falling away, but make your own eye single so that your whole body will be filled with light. Let the Holy Spirit lead you to those whose hearts He has prepared to receive the truth. Jesus is using the sword of His word, the sword of Truth, to divide between the sheep and the goats, the wheat and the tares, the believers and the beleavers. On which side will you be found?