You don’t have to wait for every single one of your doubts and fears to go away before you commit your life to Christ. You don’t have to be “strong in the faith” before you give yourself to God. It’s not the depth of your faith or the purity of your heart that saves you. It’s God’s work through Christ. Period.
Just trust him.
I love Timothy Keller’s illustration in his excellent book, The Reason for God:
Imagine you are on a high cliff and you lose your footing and begin to fall. Just beside you as you fall is a branch sticking out of the very edge of the cliff. It is your only hope and it is more than strong enough to support your weight. How can it save you? If your mind is filled with intellectual certainty that the branch can support you, but you don’t actually reach out and grab it, you are lost. If you mind is instead filled with doubts and uncertainty that the branch can hold you, but you reach out and grab it anyway, you will be saved. Why? It is not the strength of your faith but the object of your faith that actually saves you. Strong faith in a weak branch is fatally inferior to weak faith in a strong branch.
Trust him. Trust him with everything. Give him your doubts. Give him your fears. Admit them up front. It’s OK. Our God is big enough and strong enough to handle that, too. Just trust him. Reach out and grab him.
I’ve always believed in Jesus. But, I must confess, my heart’s most fundamental trust was usually somewhere else. My trust was usually in my own competency and decency. Now I see clearly how messed up that is. I’m not that good. I’m not that competent. I’m not that decent.
I’m only saved by Jesus.
Give everything to him. Transfer all of your trust to him. God will receive you and accept you, not for anything you’ve done or can possibly do in the future, but because of what Christ has done and promises to do for you.