The Bible doesn’t address the specific subject of “drug addiction,” for drugs such as marijuana, cocaine, and heroin were not mentioned in Scripture. Having said that, the Bible does speak against being under the influence of alcohol, and this would apply equally to drugs today. Consider the following scriptures (from the NASB):

*Proverbs 20:1, “WINE is a mocker, STRONG DRINK a brawler, and whoever is INTOXICATED by it is not wise.”

*Proverbs 23:20-21, “Do not be with HEAVY DRINKERS OF WINE, or with gluttonous eaters of meat; for the HEAVY DRINKER and the glutton will come to poverty, and drowsiness will clothe a man with rags.”

*Ephesians 5:18, “And do not get DRUNK WITH WINE, for that is dissipation….”

In each example cited you could exchange the word “wine” with DRUGS, or the words “heavy drinkers of wine” with DRUG ADDICTS. In each case the person is not in control of himself, but under the control of a foreign substance. In time the drug user does indeed become “addicted” to the point where he cannot function normally without the drugs. Scripture refers to this as being “in bondage to sin.” The Lord Jesus brought up this subject in John 8:32, “If you abide in My word, then you are truly disciples of Mine; and you shall know the truth, and THE TRUTH SHALL MAKE YOU FREE.” The Jews that heard Him said, “We are Abraham’s offspring, and have never yet been enslaved to anyone; how is it that You say, ‘You shall become free’” (verse 33). Jesus set them straight in verses 34 and 36: “Truly, truly, I say to you, everyone who commits sin is THE SLAVE OF SIN…If therefore the Son shall make you free, you shall be free indeed.”

If a true believer becomes addicted to drugs he is indeed enslaved to them; he is IN BONDAGE TO SIN and needs to be delivered. Thankfully, as we have seen from John 8:32 and 36, there is deliverance through the Lord Jesus Christ. He came to earth to give His life on the cross to “set us free from the penalty of our sins” (from “hell”) AND to “set us free from the power of sin” (from being bondage to drugs, alcohol, gambling, sex addiction and a host of other sins). If we walk in fellowship with our Savior by meditating on His word, praying to Him, worshipping Him, witnessing to others of Him, and having fellowship with other believers in Christ, He will indeed “set us free from sin.”

You asked if drug addiction would “block you from growing spiritually.” If we are engaged in a sinful lifestyle (such as using drugs), our fellowship with God is broken and spiritual growth comes to a halt. When we confess that sin, we can experience God’s forgiveness and deliverance from it. In 1st John chapter one, the apostle talks about the privilege we (as believers) have to walk in fellowship with God. Verse 3 declares, “Indeed our fellowship is with the Father, and with His Son Jesus Christ.” John goes on to address the possibility of sin disrupting that fellowship, but then he states the solution when we do sin, “If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness.” The moment we truly own the sin we are in bondage to our heavenly Father forgives us and He cleanses us (through the “water of the Word”—see Ephesians 5:25-26), resulting in restored fellowship with Him. This in turn results in walking in holiness and growing spiritually.

I have purposely avoided the subject of becoming “addicted to ‘legal drugs’” that have been prescribed by a doctor. This can and does happen to Christians as well, and when this occurs the believer will need prayer and support from other believers. They may even need to enter a Christ-centered Rehab program in order to experience deliverance. (262.3) (DO)