This means that the church cannot act as if it has forgotten the restored believer's offense when filling any position of service in which the person appears to be officially representing the church. The Christian organization that accepted you, believed that you would make a faithful worker, and they gave you an opportunity to prove yourself. Superficially this sounds good. However, from reading your letter, their action appears to have been contrary to biblical teaching. If not, first make a careful study of the principles of church discipline.
Church discipline is biblical, necessary, and one way of showing love.
Another way of showing love is helping believers to be successful in their Christian walk and thus avoiding problems that require church discipline. Too often, new believers start their Christian life with joy and enthusiasm, and later encounter failure and despair. Love them enough to help them be successful in their Christian walk, love them enough to restore them when they fall. This is Christ-like unconditional love.