1. Avoid the gutters.
You'll never do well in bowling if you're in the gutter very often, and the same is true spiritually. There are people you shouldn't hang around with and places you simply shouldn't go in life--the gutters, if you will. Matthew 15:14 teaches that if the blind lead the blind, they will both fall into a ditch. Don't follow the spiritually-blind, wicked people in our world. "Do not enter the path of the wicked, and do not walk in the way of evil. Avoid it, do not travel on it; turn away from it and pass on" (Prov. 4:14,15).
2. The center pin is the most important.
It's nearly impossible to get a strike without hitting the headpin (although it does happen occasionally). If you hit it, you'll generally either get a strike or be set up for an easy spare. Spiritually, we've got to hit the headpin or we'll be in trouble. Hebrews 12:1,2 instructs us to look unto Jesus and to lay aside things that would weigh us down. We must "seek first the kingdom of God and His righteousness" (Matt. 6:33). That's the center pin of Christianity, you might say.
3. If you don't succeed the first time, try again.
In each of the ten frames in a game of bowling, you get a second try, if you need it, to knock down all ten pins. Don't misunderstand, there are some things that we'll never get a second chance at (cf. Heb. 9:27), but while we are alive in the flesh we have opportunities to do better and be successful. Consider John Mark. He didn't do so well on the first missionary journey with Paul and Barnabas. He left early in the journey, and Paul was very disappointed in him. But, he was given another opportunity by Barnabas, and by the end of Paul's life, the great apostle viewed John Mark as a success (cf. II Tim. 4:11).
4. Consistency is very important.
Consistency is rewarded in bowling and inconsistency is punished. For example, if you convert a spare, then the next ball you roll will count double. If you throw a strike, the next two balls you roll will each count double (at minimum). Getting a very low count immediately after getting a spare or a strike will hurt your score in a significant way. Consistent growth and maturing is very important for Christians (cf. II Pet. 1:5-11). As followers of Christ, we must keep on keeping on--we must be consistent morally and spiritually.
5. Follow the guidelines.
Some casual bowlers are not aware that each lane is marked with a series of arrows and dots in order to increase aiming accuracy. These marks are guidelines and all of the professionals use them to achieve a high rate of consistency, leading to high scores. Spiritually, we must follow guidelines too--the Bible! God's word is what we need to be thoroughly equipped (cf. II Tim. 3;16,17). Philippians 3:16 instructs us - "To the degree that we have already attained, let us walk by the same rule." In other words, we must follow God's word to be successful.
6. You need special shoes.
Bowler's shoes have often gotten a bad name in the past for not being very fashionable, but that has changed somewhat in recent years. Some bowling shoes today look more like "normal shoes," but they still accomplish their intended function--that is, to provide a very smooth surface for the bowler to be able to slide easily on the approach. Regular shoes just do not work as well for bowling and make the sport more difficult. Christians also need special footwear, so to speak. We need to have our feet shod with "the preparation of the gospel of peace" (Eph. 6:15).
7. Score is being kept.
In the youth league (and before the widespread use of electronic scorekeeping), I learned how to keep score by hand. However, today, almost all bowling alleys have computers that keep score for you. When practicing different techniques, it is nice to simply turn off the scorekeeper. However, such is not possible spiritually. God is always watching and is aware of our behavior and thoughts. There will be a day of judgment where we give an account of how we have lived. "For we must all appear before the judgment seat of Christ, that each one may receive the things done in the body, according to what he has done, whether good or bad" (II Cor. 5:10; cf. Rev. 20:12,13).
He who has ears to hear, let him hear!