Nearly everyone understands the difference between a believer and a skeptic, but I'm not sure everyone knows the difference between an honest skeptic and a dishonest one.
An honest skeptic is someone who may have doubts about certain religious truths or doctrines, but when confronted with the evidence will face up to it and alter his life accordingly. A dishonest skeptic, however, is a person who has doubts and will never face up to the evidence. When blasted out of one foxhole of unbelief, he only takes refuge in a second. If blasted out of that foxhole, he'll just start looking for another.
In John 20:24-28 we read about Thomas, the infamous disciple for whom the well-known English epithet "a doubting Thomas" was coined. Thomas had not been with the other disciples when Jesus appeared to them after His resurrection. When Thomas rejoined them, he found them ecstatic, saying, "We have seen the Lord!!! He's risen!!!" But Thomas was a skeptic. "Unless I see in his hands the print of the nails," he said, "and place my hand in his side, I will not believe" (v.25).
Although Thomas was a skeptic, at least he was an honest one. A week after his resurrection, with Thomas present, Jesus appeared before His disciples and offered to Thomas the empirical evidence he had demanded earlier. Jesus invited him to stretch out his hand to touch His wounds. Yet Thomas didn't actually do it. He was obviously convinced without these assurances and immediately fell at Christ's feet confessing, "My Lord and my God" (v. 28).
What was it that convinced Thomas, the skeptic? Some scholars contend Thomas was persuaded because Jesus had not been physically present when Thomas said he must first see the nail prints in Christ's hands and thrust his hand into His side before he would believe. Only God could have known what Thomas required, so the argument goes. But I don't believe that's what actually won Thomas over. What finally got through to him was the presence of the living Christ, identified by his wounds. In other words, Thomas's experience of the resurrected Christ and the recognition His sufferings were for him are what changed his heart and life forever, demonstrating to Thomas as well as others the actual means by which the Gospel is validated for all skeptics.
Perhaps you are a skeptic. You say there is much in the Christian Gospel you can't understand. I agree; there is much I don't understand. You say most everything you comprehend seems contradictory to everything you previously thought. That's not surprising. For God's thoughts are not our thoughts, neither are his ways our ways (Isa.55:8). You say you can't be sure of the Bible's credibility. This is not uncommon of persons who have never been exposed to the overwhelming evidence of the Bible's inspiration and total reliability. These may be partially valid and seemingly reasonable excuses for one's hesitation to embrace the Christian faith. But have you ever faced the evidence of the power of Christ to transform the lives of those who see His love revealed in his wounds?
This is the impetus behind the incredible phenomena of the movie, The Passion of the Christ. Many people who watch this film, which so graphically depicts Christ's sufferings, come away changed. A neo-Nazi confessed to two-decade-old bombings in Norway after watching the death of Jesus in The Passion. After viewing The Passion, an Arizona man walked up to police and confessed to numerous burglaries. In Florida, a fugitive from a bank heist that happened two years earlier turned himself in after watching the movie. A man in Texas confessed to having killed his girlfriend after the death had been ruled a suicide, saying he was moved to the confession because he had seen what Christ had done to forgive him in Mel Gibson's film. In Orlando, Florida, a teenage boy who watched the film and had been bitter for years at his negligent and abusive father, found strength to forgive his father just before the young boy unexpectedly died. There is no greater proof of Gospel truth than its power to radically alter a life; making it to shun sin and want what God wants more than anything else.
The great Prince of Preachers, Charles Spurgeon, once wrote about this: "In these times, when the foundations of our faith are constantly being undermined, one is sometimes driven to say to himself, 'Suppose it is not true.' As I stood, the other night, beneath the sky, and watched the stars, I felt my heart going up to the great Maker with all the love I was capable of. I said to myself, 'What made me love God as I know I do? What made me feel an anxiety to be like Him in purity? Whatever made me long to obey my God cannot be a lie.' I know that it was the love of Jesus for me that changed my heart, and made me, though once careless and indifferent to him, now to pant with strong desires to honor Him. What has done this? Not a lie, surely. A truth, then has done it. I know it by its fruits. If this Bible were to turn out untrue, and if I died and went before my Maker, could I not say to Him, 'I believed great things of thee, great God; if it be not so, yet did I honor thee by the faith I had concerning thy wondrous goodness, and thy power to forgive'? and I would cast myself upon His mercy without fear. But we do not entertain such doubts; for those dear wounds (the wounds of Christ) continually prove the truth of the Gospel, and the truth of our salvation by it. Incarnate Deity is a thought that was never invented by a poet's mind, nor reasoned out by a philosopher's skill. Incarnate Deity, the notion of the God that lived, and bled, and died in human form, instead of guilty man ... is itself its own best witness. The wounds are the infallible witness of the Gospel of Christ."
Please don't misunderstand me. I'm not saying we should throw away our intellects. What I am saying, however, is that if you are an honest skeptic as Thomas was, our Lord will provide answers for your inquiries. God gave you a mind as well as a heart, and He is willing to address your intellectual needs. But I suggest what will ultimately convince you of the truth of the Gospel will not be the reasoned arguments, though they may be important stepping stones, but an experience with the living Christ and His love demonstrated in His death for you. Such revolutionizes a life and causes one to fall on their knees before Him, saying, "My Lord and my God."
This can happen to you, but only if you are honestly open to it.