As a Christian I have found the heaviest weight I work-out with now has to do with pushing away more that pulling down. Trying to keep the doors close on the things that the Old-Man (your old self) tries to open is a daily challenge. Everyday the struggle to keep those doors and windows close equate to a good weight-pump and/or cardio round. Training is a must to keep in shape for both. As in any good workout program there has to be consistency. God has built into the body great memory and it will bounce back to time off if it is brief. If the body is in shape it withstands body-blows, mental-mistakes and enemy-challenges. An in-shape body will do things above what you feel you can do during stressful situations.
However the longer you stay away the harder it is to get back into shape. Like a good workout if you don’t lift the Bible daily it gets harder and harder to deal with what comes at you. Without dropping down to you knees daily the voice of God gets weaker and weaker to your ears. And with the wrong meditation the words that flow off of your tongue sounds more and more like what’s already out there.
Your training only gives you what you put in. The Old-Man has been training for a long time. And, it’s natural to him. He is a lot stronger than you think. Only Spiritual training will help you keep him out.
Leaving Our Old Ways Behind (Ephesians 4:17-24)
This I say therefore, and affirm together with the Lord, that you walk no longer just as the Gentiles also walk, in the futility of their mind, being darkened in their understanding, excluded from the life of God, because of the ignorance that is in them, because of the hardness of their heart; and they, having become callous, have given themselves over to sensuality, for the practice of every kind of impurity with greediness. But you did not learn Christ in this way, if indeed you have heard Him and have been taught in Him, just as truth is in Jesus, that, in reference to your former manner of life, you lay aside the old self, which is being corrupted in accordance with the lusts of deceit, and that you be renewed in the spirit of your mind, and put on the new self, which in the likeness of God has been created in righteousness and holiness of the truth.