Summary: We look at the qualifications of a priest and apply them to us as Christians
Leviticus 21 qualifications for priesthood
What does this have to do with me? We don't need priests. We as Christians are called priests. 1 Peter 2:5-9
 Ye also, as lively stones, are built up a spiritual house, an holy priesthood, to offer up spiritual sacrifices, acceptable to God by Jesus Christ.  Wherefore also it is contained in the scripture, Behold, I lay in Sion a chief corner stone, elect, precious: and he that believeth on him shall not be confounded.  Unto you therefore which believe he is precious: but unto them which be disobedient, the stone which the builders disallowed, the same is made the head of the corner,  And a stone of stumbling, and a rock of offence, even to them which stumble at the word, being disobedient: whereunto also they were appointed.  But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light:
The time of priests was shown to be over when God ripped the veil it showed we can come to God. We are priests now we don't need another's authority. We have the authority through the blood of Christ. We are also priests not only in sense of going to Him but also serving Him. Hebrews 13:15-16 we offer the sacrifice of praise.
Hebrews 13:15-16 KJV
 By him therefore let us offer the sacrifice of praise to God continually, that is, the fruit of our lips giving thanks to his name.  But to do good and to communicate forget not: for with such sacrifices God is well pleased.
17-blemish- all defects that are about to mentioned
18- blind- spiritual blindness 2 Peter 1:9 But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins.
18- lame- some believers don't walk they just think about the injury that put them into this situation. Ephesians 4:1 I therefore, the prisoner of the Lord, beseech you that ye walk worthy of the vocation wherewith ye are called,
18- flat nose-idea of a mutilated face. No joy being shown. Galatians 5:22-23 But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, 23 Meekness, temperance: against such there is no law.
18- superfluous- having extra. For example 6 fingers or toes. Can't add to what Gid wants. Revelation 22:18 For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book:
19- broken footed and broken handed- can't do the work. John 9:4 I must work the works of him that sent me, while it is day: the night cometh, when no man can work.
20- crook backed- not able to lift problems. Can't handle the weight. Matthew 11:28 Come unto me, all ye that labour and are heavy laden, and I will give you rest.
20- dwarf- stunted growth as a believer. 2 Peter 3:18 But grow in grace, and in the knowledge of our Lord and Saviour Jesus Christ. To him be glory both now and for ever. Amen.