Matt 5:48: "Therefore you shall be perfect, just as your Father in heaven is perfect.”

Greek - teleios from 5056; complete (in various applications of labor, growth, mental and moral character, etc.); neuter (as noun, with 3588) completeness: KJV-- of full age, man, perfect.

This same word is used in Matt 19:21 Jesus said to him, "If you want to be perfect, go, sell what you have and give to the poor, and you will have treasure in heaven; and come, follow Me."

The is the same Greek word used in the majority of the texts with the word perfect with a few exceptions.

Obviously Jesus is not speaking of moral perfection but mature in faith because you care for others in need instead of yourself. Neither is Jesus promoting works as a means of our perfection. The bible teaches that perfection in this body will not occur until we have a transformation of the body by the resurrection that will change it from mortal to immortal (Rom.8).

2 Cor. 7:1: “Therefore, having these promises, beloved, let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God.”

The fear of the Lord is the beginning of wisdom, obedience in our sanctification helps us to be set apart for our masters use.

Luke 1:3: “it seemed good to me also, having had perfect understanding of all things from the very first, to write to you an orderly account, most excellent Theophilus.” akribos- exactly, accurately, diligently.

Both Rom .12:2: “And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.”

2 Cor. 12:9: “And He said to me, "My grace is sufficient for you, for My strength is made perfect in weakness.”

Is the Greek word teleioo 5048 from 5046; (and other forms means to complete, i.e. (literally) accomplish, or (figuratively) consummate (in character): - consecrate, finish, fulfil, make) perfect.

Gal 3:3 “Are you so foolish? Having begun in the Spirit, are you now being made perfect by the flesh?”

Greek- epiteleo; from 1909 and 5055; to fulfill further (or completely), i.e. execute; by implication, to terminate, undergo: KJV-- accomplish, do, finish, (make) (perfect), perform (X -ance).

2005 epiteleo-1) to bring to an end, to accomplish, to perfect, to execute, to complete

a) to take upon oneself

b) to make an end for oneself, to leave off

2) to appoint to, to impose upon

Paul is saying one cannot become spiritually mature by using the law

Eph 4:13: “till we all come to the unity of the faith and of the knowledge of the Son of God, to a perfect man, to the measure of the stature of the fullness of Christ”

Greek- teleios; complete (in various applications of labor, growth, mental and moral character, etc.); neuter (as noun, with 3588) completeness:

Col 4:12: “ laboring fervently for you in prayers, that you may stand perfect and complete in all the will of God.”

…teaching in all wisdom, (application) to present every man perfect in Christ the same word for finished for Christs sacrifice. Greek - teleios- 1) brought to its end, finished 2) wanting nothing necessary to completeness 3) perfect b) used of men, full grown, adult, of full age, mature, complete (in various applications of labor, growth, mental and moral character, etc.); neuter (as noun, with 3588) completeness: In Christ Jesus.

1Thess 3:10: “night and day praying exceedingly that we may see your face and perfect what is lacking in your faith?

James 1:4: “But let patience have its perfect work, that you may be perfect and complete, lacking nothing.

James 2:22: “Do you see that faith was working together with his works, and by works faith was made perfect?

I Jn 4:18: “There is no fear in love; but perfect love casts out fear, because fear involves torment. But he who fears has not been made perfect in love.”

It means to be mature, complete without defects of moral character (neuter). What it does not mean is that we are perfect in the sense of having no sin and being an exact image of Christ. This can only take place at the resurrection.