It is important for us to remember that we are imperfect people chosen by God to do His perfect will. God doesn't wait until we're perfect to use us. If He did, none of us would be used!
Satan will try to use our weaknesses against us. He'll tell us that we're unworthy, unfit, and unqualified. But God uses our weaknesses to make us stronger. In 2 Corinthians 12:9, Apostle Paul wrote:
"Satan's angel did his best to get me down; what he in fact did was push me to my knees. [God] told me, ‘My grace is enough; it's all you need. My strength comes into its own in your weakness'" (The Message Bible).
Although we should always pursue spiritual growth, the Word of God reminds us that we don't have to be perfect to be used by God. David committed adultery and murder. Jacob was a liar. Elijah's faith in God wavered. And Solomon (described as the wisest man on earth) made unwise choices.
Be confident in knowing this: God doesn't want us to stay where we are, but He'll use us right where we are. More importantly, if we are able to be honest about our shortcomings, God can use our weaknesses to make us — and other people — stronger.