All Christians have, or have had, various doubts about the truth claims of Christianity. For the Christian, this can be most unpleasant. However, as we move through a season of doubt, asking questions, receiving answers, praying for more faith etc., we generally find that our faith has grown and is more solid for the process of working through the issue. This is easy to say but for some people, very difficult and painful to do.
Having doubts is not what determines if a person is a Christian. God is faithful (2 Timothy 2:13) even when we are not. The Bible tells us that everyone who believes in Jesus Christ will be saved (Romans 8:38-39, 1 John 5:13). God wants us to be confident in our salvation, so working through your doubts is very important!
One theologian likens doubts to human antibodies that can protect us (our faith) in the future. After having been exposed to a doubt or concern, and successfully resolving it, the antibodies remain with us to quickly dispel another concern in the same area. This process makes sense in terms of facing one’s doubts and receiving solid Biblical answers. It is quite dangerous to leave a doubt in one’s mind and NOT having that doubt resolved! It is important to face one’s concerns and to ask questions and seek answers until that issue is resolved. After some 2000 years, it is likely that someone else has had the same doubt as you!
We can look at the Bible to see how Jesus treated people who had honest doubts, for example Thomas (John 20:24-29) and John the Baptist (Matthew 11:1-11 and Luke 7:18-30). Concerning the doubts of John the Baptist, Gary Habermas wrote:
“It’s not just the question itself that’s so staggering. If it came from someone in the crowd, it would probably be dismissed by many readers as being from someone who lacked faith. What turns it into such a bombshell is because it comes from John the Baptist, God’s chosen forerunner for Jesus, predicted in the Old Testament (Isa. 40:1-3). Was John in danger of throwing his faith overboard?
First, let’s note Jesus’ immediate response. He didn’t react in a vindictive fashion, such as by telling John to shape up, or to live up to his reputation, or by quoting verses to him and reminding him of his special position as the chosen herald of the Lord’s coming. Neither did He, as some Christians would suggest, ignore evidences that might address John’s need. Rather, He cured a number of suffering people right there in front of the two messengers and then instructed them to go tell John what they just witnessed. Apparently, Jesus thought that there was some relevance between His healing miracles and John’s faith. That is a lesson in itself.”
So for people with honest questions Jesus just answered their queries without condemnation. We often have doubts because we just do not know the information that would provide the answer. That is why it is so important that you share your questions with your minister so that the information can be received and you may move on. Should your minister not have the answer (and some do not) persist in your search for the appropriate answer.
If your reasonable question should receive an answer of, “You just have to have faith”, it might be good to ask someone else! It is most likely that the answers you seek are readily available. It is good to remember, however, that God does tell us that he does not reveal all to us (Deuteronomy 29:29) and that His ways are not our ways (Isaiah 55:9).
For many people the case for Christianity is a cumulative case of evidences. However it is quite clear that no one comes to Christ without the involvement of the Holy Spirit (John 16:7-11). After a certain point, when so much solid information is investigated and accepted, many people are ready to make a commitment considering the alternative, unbelief, to be impossible.
“The remedy for doubt is faith, and faith comes by hearing the Word of God (Romans 10:17). God gave us the Bible as a testimony of His works in the past, so we will have a reason to trust Him in the present. “I will remember the deeds of the LORD; yes, I will remember your miracles of long ago” (Psalm 77:11). In order for us to have faith in God, we must study to know what He has said. Once we have an understanding of what God has done in the past, what He has promised us for the present, and what we can expect from Him in the future, we are able to act in faith instead of doubt.”
There certainly appears to be a dynamic between knowledge and faith. Regarding the Holy Spirit’s dynamic and faith, there is no doubt. We have a faith in an object based upon a knowledge God has already provided us proving that He can be trusted to do the things He has promised to do for us in the future.
 Gary R. Habermas, The Thomas Factor (Nashville: Broadman & Holman, 1999), NEED PAGE NUMBER
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Don’t Waste Your Doubt: finding deeper faith on the other side
Five Things To Do When You Are Struggling with Faith Doubts by Natasha Crain
The Thomas Factor by Gary Habermas
Dealing With Doubt by Gary Habermas
 Gary R. Habermas, The Thomas Factor (Nashville: Broadman & Holman, 1999), page##