Then Jesus said to his disciples, “If any of you wants to be my follower, you must give up your own way, take up your cross, and follow me. If you try to hang on to your life, you will lose it. But if you give up your life for my sake, you will save it. And what do you benefit if you gain the whole world but lose your own soul? Is anything worth more than your soul? ~ Matthew 16:24-26 NLT
Following Jesus is a lifelong process. You are always learning and growing. There is always more to learn.
However, serving, preaching, and sharing happen throughout the process. They’re not a pinnacle after you’ve learned everything. They are part of the discipleship process.
The twelve apostles were sent out to serve, preach, and even heal long before they felt ready. They didn’t even have the Holy Spirit yet, for it hadn’t been given. But long before this, God spoke through the prophet Isaiah, “Do not fear, for I am with you; do not be dismayed, for I am your God. I will strengthen you and help you; I will uphold you with my righteous right hand.” (Isaiah 41:10 NIV)
You shouldn’t wait until you’re ready to serve others and preach the Gospel. You will never feel ready. And the results of these activities come from God anyway–not you.