We know from Paul's second letter to the Corinthians (2 Cor. 5:10), that we must all appear as Christians (Christ-Ones), (sealed in the heavenlies), before the Judgement seat of Christ. There is the same comment in Rom. 14:10. In 1 Cor. 3:10-15 Paul clearly describes that which is of value in the Christian, and that which is not will be burnt up at the time of the Bema Judgement (examination). [The Interlinear Strongs numbering for Judgement - seat of Christ 968, crossed referenced to Strongs Concordance = Bema - (bayma), - a step - a rostrum – i.e. tribunal, judgement - seat, set foot on, throne]. What Paul does not do is to say what in precise terms should be built upon the foundation of Christ's Salvation in the individual. He does lay out the obvious, but as the freewill is so much involved in the individual as to which elements over the lifespan of a person will be added, he is careful not to dictate the detail.
We are told in 2 Tim. 2:15 that to work at the Word is critical for every Christian. That involves the freewill of the person. Unfortunately in this day and time many Christians follow slavishly the statements made by group leaders, rather than study for themselves. They convince themselves that to belong to a good Group, and to follow the Leaders words and teachings gives them all that is required to enter heaven!
To belong to a good Group is important, but it is also important to get to know God's Word, otherwise the statements and teaching of the Leader cannot be checked!
As has been shown above, building on the Foundation of Christ's Work on Calvary's Cross, is the responsibility of all who have come to Him in faith to be Saved. As we used our freewill to turn to Him, we need for the rest of our lives to use the same freewill to become more like Him day by day, and that is achieved by a partnership of our will and His, which gives power for the effort!
We can with certainty state that the Timothy reference to showing oneself a good workman in the Word is safe ground. We also know that as we know more of the Word in Truth it is also clearer what other materials can be used for the building. It is also safe ground to work at one's mind "becoming more Christ like", (1 Cor. 2:16) and we are also told that it is the work of God to work at the Faith, (1 Thess. 1:3), (2 Thess. 1:11), (1Tim. 6:12), which in itself brings in the other mentioned qualities.
In summary: the Holy Spirit with the willing cooperation of the individual clearly shows what is good and acceptable for building materials in the Christian.
What is crucially important is to differentiate the Bema experience for the Christian, from the various judgements that will apply to all people who have ever lived except the Christian at the Great White Throne Judgement (Rev. 20:11) at the end of the Millennium Ae. These people are judged on their individual lives and all they ever did. A Christian does not come into that Judgement category, as they are washed clean in The Blood of the Risen Lord at the moment of True acceptance. Then there is only the trimming away by burning, of those things from that moment to the end of their lives, which are unworthy and unacceptable.