Moderation is perhaps the governing concept for a Christian view of bodybuilding / weightlifting. First Timothy 4:8 teaches, “For physical training is of some value, but godliness has value for all things, holding promise for both the present life and the life to come” (emphasis added). Physical fitness is important, and as this verse states, it does have some value. We are physical and spiritual beings, and the condition of the physical body undeniably can impact the spirituality of a person. Surely part of “glorifying God in your body” (1 Corinthians 6:20) is keeping it in reasonably good physical condition. Bodybuilding can definitely be a part of a Christian’s physical fitness program.
At the same time, as with many things in this life, bodybuilding, if taken to the extreme, can become an idol. Eventually, a point is reached where there is no true value in adding more muscle. In fact, too much muscle can be hazardous to your health, as it puts additional strain on the heart. Bodybuilding / weight lifting can become an addiction and/or obsession. While this is much more often an issue with men, it can be an issue for women as well. Striving for bigger and stronger muscles, taken to the extreme, is nothing but vanity (1 Samuel 16:7; Ecclesiastes 1:2; 1 Peter 3:4). Once we allow our physical appearance to become more important than our relationship with God, it has become an idol (1 John 5:21).
“So, whether you eat or drink, or whatever you do, do all to the glory of God” (1 Corinthians 10:31). That is the key question. Does bodybuilding / weightlifting glorify God? If it is done to increase fitness, strength, and tone, and thereby health, yes, it can be done for God’s glory. If it is done out of vanity and pride, or from an unhealthy obsession with getting bigger and stronger, no, it does not glorify God. How should a Christian view bodybuilding? “Everything is permissible for me”—but not everything is beneficial. “Everything is permissible for me”—but I will not be mastered by anything. Everything is permissible”—but not everything is beneficial. “Everything is permissible”—but not everything is constructive” (1 Corinthians 6:12; 10:23).
 Got Questions Ministries. (2010). Got Questions? Bible Questions Answered. Bellingham, WA: Logos Bible Software.