to knowledge self-control, to self-control perseverance, to perseverance godliness,
to godliness brotherly kindness, and to brotherly kindness love
For if these things are yours and abound, you will be neither barren nor unfruitful in the knowledge of our Lord Jesus Christ."
2 Peter 1:5-8 (NKJV)
Have you ever heard something being advertised as the one thing that you need for this or that? Often this is the kind of thing that is presented for those who want to succeed in business, financial things, or areas of self-help and improvement, and someone is offering to show them that one key thing that they need to do. But the real truth is, the majority of the time there is not just one key thing, but many things that are necessary in achieving these goals and having success.
It is unfortunate, but this kind of mentality is sometimes seen in Christianity, where something is presented as "that one key thing" that is needed to make someone a super-spiritual Christian, or to give someone the breakthrough in their life, or the thing that is needed to move forward in the plan of God. But, just like in the secular world, the majority of the time, what believers need is a combination of several things to help them be what they ought to be and to do what God wants them to do.
One thing you don't see presented in the Bible is that there is just one key thing that you need to be a spiritual success. As it tells us in 2 Peter 1:5-8, there are many things that are necessary for believers, and there are things that we need to add to our faith in order to be fruitful. Don't be misled by the idea that all you need is that one key thing in life. Put God's Word into practice, follow the direction of the Holy Spirit, and you will find what it is that you need, to do what God has called you to do.