#1: You must believe that Jesus Christ is God's Son, that you have sinned, and that He is willing and will forgive you and save you if you ask Him. He must be the Lord of your life.
#2: You must say "yes" to whatever He wants you to do, whatever He wants you to say, wherever He wants you to go.
A lot of us get stuck on the second part or we say, "Yes, God, I'll do, say, and go wherever You want", but then we think, "What if He calls me to go somewhere else, asks me to give up everything familiar, or wants me to do something unusual for Him?" Well, here's the deal: saying "yes" to God's calling means you will encounter risk and resistance, but you'll also receive the reward of obeying Him.
So, think about it, are you basing your answer on fear or faith? The ultimate object of God's calling is to glorify God and make Him famous, but do you hesitate, trying to weigh everything that might go wrong against what might go right? "Count the cost!" you say, but is that an excuse you're hiding behind rather than a valid reason? We all struggle with this. If you look deep- really deep (or not so deep)- inside, is it your fears or your faith that is ruling your life? Did you know that your part is only to say "yes" to God and not to worry about the details or make it all fall into place?
Where God guides, God provides.
Whenever someone says "yes" to God, a great victory is won, but that's only part of the process. Every day after that- really, many times every day after that- that person must continue to choose faith over fear. God never said life would be comfortable, but He did say He'd always be with us in it.
So what's holding you back? What will be the results of obeying Christ?
You will never know until you jump in.
Today, if you hear His voice, don't harden your heart. Don't let fear control you any longer. Go to God and tell Him, "God, I hear Your voice, I know what You're telling me, but I'm scared. I don't know what to expect; I don't know what all You have in store for me, but I want to trust You. I want to say 'yes' to You..." Be at peace. He'll do the rest.