To be fruitful for God’s Kingdom, you need to do a couple of things.

1. Lay a good foundation. Repent, “Repent, for the kingdom of heaven is at hand.” Mathew 4:17. Confess any sins and turn from the sin.
2. Grow your faith. Faith comes by hearing and hearing of God’s word (Romans 10:17).
3. Work out your Character with all diligence.   

“But also for this very reason, giving all diligence, add to your faith virtue, to virtue knowledge,  to knowledge self-control, to self-control [a]perseverance, to perseverance godliness, to godliness brotherly kindness, and to brotherly kindness love.” 2 Peter 1:5-7

And do not lay again a foundation of repentance to dead works (sin).

“For if these things be in you, and abound, they make you that ye shall neither be barren nor unfruitful in the knowledge of our Lord Jesus Christ.” 2 Peter 1:8