You and I will never be perfect in this life; as long as we live on this earth we'll still be sinners, and our ability to commit sin will always be with us. The Bible warns, "If we claim to be without sin, we deceive ourselves and the truth is not in us" (1 John 1:8).
I don't doubt your friend's sincerity; he may well be a good person, especially when compared with people who aren't so good. But God isn't only concerned with our outward actions. God is also concerned about what goes on inside of us -- with our motives and our inner thoughts. Are we ever jealous of others? Do we ever covet something for ourselves? Are we ever tempted to say something that's hurtful or not quite true? Do we love others the way Jesus does?
Only in heaven will we be perfect and without sin, because only in heaven will we become like Christ. The Bible says, "We know that when he appears, we shall be like him, for we shall see him as he is" (1 John 3:2). That should be a great encouragement to us, because it reminds us that someday our burden of sin will be destroyed.
Does this mean we shouldn't seek to become more like Christ? No, of course not. At the beginning of each day, ask God to help you have the attitude and character of Christ in all you do and think and say. Like the Apostle Paul, ask God every day to help you "press on toward the goal ... heavenward in Christ Jesus" (Philippians 3:14).