More than a few of us are likely often tempted to ask the Lord if He's really there. While He isn't likely to appear to us as He did with the apostles, you can be assured that He is calling out to each and every one of us. Take your doubt to Jesus and begin a conversation with Him. Just as He did with Thomas, He'll meet us where we are at any given time - even (and perhaps especially) in our doubt and unbelief.