Matthew 5:45-48
Mat 5:45 (KJB)
That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust.
One becomes a child of God through salvation in the Lord Jesus Christ. The four Christian principles which was spoken of in the last verse, when they are partaken of, give practical evidence that one is a true child of God. In other words, when we look at the rest of the verse, it should not matter who we do good for, whether they are a believer or unbeliever. God does not withhold the rain or the sun from the unbelievers and just allow them to be enjoyed only by the believers. The unbeliever skydives, swims, surfs, sows and plants crops, and enjoys all of the creation as much as the believer does. As God does not withhold goodness from the unbeliever, neither should we or else we would be just like the Pharisees.
Mat 5:46 (KJB)
For if ye love them which love you, what reward have ye? do not even the publicans the same?
It is very easy to love those who love you or to be friends with those who are our friends. What reward does that bring? (Luke 14:13-14 KJV) But when thou makest a feast, call the poor, the maimed, the lame, the blind: {14} And thou shalt be blessed; for they cannot recompense thee: for thou shalt be recompensed at the resurrection of the just. To love those that are hate filled or to love those that are the despised or outcasts of society shows a true and pure love. Loving those who love you is a type of love which offers recompense because if someone invites you to their house for dinner, then you will in turn invite them for dinner. Those who are poor or those who have disabled bodies cannot recompense you but your recompense comes at the resurrection, from Jesus Himself, not from some neighbor who feels compelled to invite you because you invited them.
Mat 5:47 (KJB)
And if ye salute your brethren only, what do ye more than others? do not even the publicans so?
Salute - Embraced, cherished or greeted
One who salutes their own brethren are no better than the unbelieving publicans who socialize with their own kind. The true believer is to show they are more than just a mere religious group and to show compassion and love to those who are not of their social strata. The publicans would never socialize with someone who is lame or sick because they were considered the outcasts or the dregs of society and it would not look good if they were seen with those who were outcasts. Letís bring it up to today. When was the last time a multi-millionaire came to your house? When was the last time some CEO of some company looked at you as his equal? These people only salute those of like status and wealth. Jesus is saying that we must have a different outlook and realize the fact that within every person, wealthy or not, is an eternal soul and their social status will mean nothing at the Judgment Seat of Christ. Their social standing means nothing in the Kingdom of God either, because we are all equal at the foot of the cross. If we salute only those of like status, then everyone will make an assessment that Christians are just like the rest of the world.
Mat 5:48 (KJB)
Be ye therefore perfect, even as your Father which is in heaven is perfect.
Jesus now sums up the teachings that we are to be perfect as our Heavenly Father is perfect. Since we are fallen beings and still have the sin principle living within our flesh, we will never be practically sinless on this earth, we could never be as sinlessly perfect as God is. What is in view here is the true believer is to emulate God in such a way that we live our lives exuding the principles which Jesus just taught such as goodness, kindness, caring for others, love, non-prejudicial outlook on unbelievers, blessing them, etc. We are to embrace those characteristics of God and make them a true part of our daily lifestyle.