The above quotation, when applied to our lives, rings true. How we spend our time and what we allow to occupy our attention tells others what we really are and that may be dramatically different from what we claim to be.
Professing to be Christians does not mean that we are living as the children of God should. Unless we conform our thoughts and actions to the word of God and the example set by His Son and be busy about the Father's business, others will know and the Father will know that even though we claim to be dedicated to the Lord, our affections lie elsewhere.
What are you "busy about?" Is it your job? Does it take all of your energy and most of your time? Is your main interest in life the amassing of "things?" Do you use all spare moments in some recreational pursuit? If any of these apply, you need to take stock and channel your "busyness" into that which is more profitable -- serving the Lord. If one is going to be Christ-like, he must have the mind of Christ (Phil. 2:5). It is evident that Christ's attitude while on earth was to be busy about His Father's business (Luke 2:49). Such passages as John 4:34, 6:38 and 9:4 show that He continually focused on doing the will of God. In turn, He taught His disciples the most important thing in life for them was to do God's will and be concerned with His kingdom first (Matthew 6:33).
The apostle Paul zealously applied himself to the will of God. He was always busy serving the Lord. He constantly pressed on so that he could attain his goal to live a life pleasing to God so that he would gain an incorruptible crown (Phil. 3:7-16). On the other hand, Demas, a fellow-worker with Paul, busied himself with other things -- the things of this world (2 Tim. 4:10). His love for this "present world" ultimately caused him to abandon both Paul and the Lord.
When Jesus was in the house of Mary and Martha, two sisters who lived in Bethany, both of them were busy. In the eyes of the world and even in the eyes of her sister, though, one seemed to be idle (Luke 10:38-42). Martha was " distracted with much serving" (Luke 10:40). She busied herself seeing that the needs of her guests were satisfied. She became so anxious about it that it consumed her. Her sister Mary sat at the Lord's feet not wishing to miss a single word He was saying. She busied herself listening to Him knowing that it was the most important thing she could be doing. When Martha complained to Jesus about her, He told her not to worry about so many things that, in reality, were not necessary. Rather, she should devote herself and her time, as Mary had, to "the one thing that is needed" -- hearing and obeying the word of God. Again, with what are you busy? Is it your job, a hobby, material possessions or worldly pleasures? If so, what does that say as to what you really are? What do others think is your first love? What is the Lord's view of you?
A question that has been used before, possibly overused, but nevertheless is relevant to our line of thought is, "If you were tried for being a Christian, would there be enough evidence to convict you?" If you were "busy about" that which you should be busying yourself with, it would be evident to all what you really are. All would know you are a Christian, see the glory of God in you and glorify your Father in heaven (Matthew 5:14-16). More importantly, the Lord would know. If you claim to be a Christian, get busy doing the will of the Lord.