When the topic of the assurance of salvation comes up the reasons for doubt are often brought into the conversation. A popular excuse to doubt the salvation they claim they have is, they say they do not doubt Christ, but doubt themselves. They see that their obedience is weak, their love is cold, their spiritual fruit is not flourishing and they "feel" unsaved because of the guilty feeling over their sin. What makes things even more confusing is other people trying to comfort them, wrongfully go further in saying that these doubts are probably the best evidence that a person is saved in the first place. Let us look at a few issues that might help to unravel this mess and direct us in a proper gospel focus.
1) As God's people, we are NEVER directed anywhere in God's word to look within ourselves, our performance, or even the work of the Holy Spirit in us, to become the basis of our assurance of salvation. Christ and Him crucified as our Representative, Substitute, and Mediator is our only hope and confidence for acceptance with a holy God. Satan will always try to get us to look inward instead to Christ alone. Doubt is simply what it is ----- sinful unbelief.
2) We must ALWAYS doubt ourselves. If we get to the point that we have confidence in ourselves then we are in big trouble and headed for no small fall. Hard lessons will no doubt follow if God's people venture off track on the issue of assurance. The Lord has a way, many ways, of squeezing out the remaining self-righteousness and bringing it to the surface so as to be repented of by reminding us NOT to trust ourselves for salvation.
3) Faith is sometimes weak, very weak. God guides and directs our lives in His providence in such a way that He teaches, molds, conforms, and lovingly causes us to grow in His grace. How does this work? The word of God, the gospel, directs us to lean on, trust in, hope in, rest in, count on and believe in the Lord Jesus Christ as the only answer to the sinner's needs in salvation. This gospel of grace is the means whereby God causes our faith to be strengthened. This is a means not to be neglected.
4) As mere human creatures we cannot trust our feelings. Do not fall prey to this wicked mysticism. Feelings are constantly changing whether we admit it or not. We are changeable. We are encouraged in the gospel of grace to trust Christ, the One who NEVER changes. He is the same yesterday, today, and forever.
5) Lastly, there is a false gospel in the world that presents a failed christ who did not accomplish the complete work of salvation. This false gospel leaves conditions of merit to be earned by men since the false christ did not finish what was required of God in salvation. If a person believes such a false gospel he would do well to doubt because he is not even saved in the first place, but rather deceived. This false gospel is the most popular form of religion in the world and even comes in the name of “christianity”. Watch out for the lies of a system of salvation that puts salvation in the lap of the sinner to accomplish. God's conditions are too demanding and His standards are way too high for man to even come close. Christ Jesus The Lord is the only One who is able.