For those who are struggling with intellectual doubts:
Focus attention only on the issues that make or break the core essence of Christianity such as the resurrection of Christ and the existence of God. Don’t spend time on more ancillary issues such as creation/evolution, the world-wide flood, or the perfect harmony of the individual authors’ truth claims. These, either way you go with them, do not effect the essence of the Gospel message. If Christ rose from the grave as an historical reality, then all else, though they may shake, crack, or crumble, do not have the sting of apostasy on board.
For those who are struggling with emotional doubt
Remember that our emotions do not have a determinative vote in truth. We must be willing to trust God even when the truth claims we are asked to believe seem to militate against our moral compass. Remember that God gave us our emotional dispositions and he knows the struggles we have, yet he tells us that he loves everyone more than we do and knows what he is doing. In this sense, he holds out his hand and says “Trust me. I know you would do things different, but just trust me.”
For those struggling with experiential doubt
Remember that the lot life hands us will often be filled with experiences that differ from the experiences we would bring about were we in control of the world. Contrary to popular opinion, the Bible does not guarantee anything but suffering, pain, and perplexity as we attempt to live for God. This is why so much of the Bible points our thoughts to the unseen future that God has promised. Often times we “punt to the eschaton” not as a cop-out, but because in it is our true hope where tears will be no more.