Can God use me?

Can God use me despite my sinful past? I have found that God uses unqualified people to accomplish God’s spiritual purposes. Here are the following God’s CHOSEN/CALLED unqualified people to serve Him.
1. Lot got drunk and committed incest.
2. Abraham doubted God and committed adultery.
3. Jacob deceived his father.
4. Moses murdered.
5. David murdered and committed adultery.
6. Jonah got angry with God (in a sinful way)
7. Paul (Saul) murdered Christians
8. All 12 of Jesus disciples were not qualified to be the Apostles however Jesus called them.

At the same time, God expect leaders to have good reputation. In the book of Titus, the requirements are: Show integrity, seriousness and soundness of speech that cannot be condemned, so that those who oppose they may be ashamed because those have nothing bad to say about them. That teachers are to say "No" to ungodliness and worldly passions, and to live self-controlled, upright and godly lives in this present age. In 2 Corinthians 7:2 says that we "make room for others in our hearts. We have wronged no one, we have corrupted no one, we have exploited no one." This is where "accountability" comes in. In 1 Timothy 3:1-3: If anyone sets his heart on being an overseer, he desires a noble task. Now the overseer must be above reproach, the husband of but one wife, temperate, self-controlled, respectable, hospitable, able to teach, not given to drunkenness, not violent but gentle, not quarrelsome, not a lover of money.

Integrity is a major problem for me. My dictionary defines integrity as 'consistency and sincerity, with no deception or pretense'. Integrity's overriding quality is wholeness. A spiritual leader ought to be humble, self-effacing, self-sacrificing, modest, clean living, free from the love of money, eager to promote the honor of God and just as eager to disclaim any credit or praise on self-promotion that inspection, ethical standards will be high and personal life is above reproach.

Another is Reproach: an expression of rebuke or disapproval; the act or action of reproaching or disapproving ; a cause or occasion of blame, discredit, or disgrace; to express disappointment in or displeasure with (a person) for conduct that is blameworthy.

When a pastor should remove himself from position? Would anyone follow a pastor who do not practice what he teach? When a local church lose their respect for their pastor, it is a sure sign that this pastor has outlived his usefulness to that congregation. It is important for us to relize that the pastor-church relationship is very sensitive and vitally important issue. I believe the hardest part as a Christian is being like-Christ and try to live in a "blameless" life. We do not expect our pastors to be the only ones who are acting like-Christ and live in a blameless life. ALL members of the Church must live in a blameless life, be the shining light to the lost and bring them to Christ. The pastor should be known as a man of Christian character and conduct and there should be demonstrable evidence of his mature, Christian character. God is obviously concerned with the character of the men put in the office of pastor.

Once a pastor fall from "serious sins", I will forgive him as a fellow Christian however at the same time, if he gets restored becoming a leader, I will not stay with the Church or follow his teachings again.