The great altar was made of brass, and only gifts laid on that altar were truly sanctified to God. Only the Holy Spirit can determine the place of jewels in our lives. These stones symbolize the valuation of souls. Upon those precious jewels, worn over the heart and upon the shoulders of the High Priest, were inscribed the names of the 12 tribes of Israel. Only the Holy Spirit can determine the place of wood in our lives.
Wood symbolizes the consecration of work.
Wood undergirded most of the structure of the tabernacle, and so speaks of the multitudinous tasks that need to be done in the life of the church. What these jobs are and how they are to be performed must be determined by the Holy Spirit. He alone can fit and guide us. But, once again, the Holy Spirit fitted Bezaleel and Aholiab to develop abilities in the work of God. On the contrary, God used what was natural and enhanced it by that which was spiritual.