Neglecting the sacraments is just like neglecting any other means of grace; worship, prayer, fellowship with God's people, etc.
While they are not necessary for salvation in the strictest sense, we must also affirm that regular, willing participation is part of the normal Christian life. They help us to grow in Christ and experience His salvation at the intended level.
They are not the means of our justification, but neither are they optional for our sanctification.
“not forsaking the assembling of ourselves together, as is the manner of some, but exhorting one another, and so much the more as you see the Day approaching.” (Heb. 10:25)
“assembling of ourselves together” includes all the means of grace given to the Church community; worship, prayer, sacraments, fellowship.
Coming from a Baptist background, we do not call them “sacraments.” Rather, we call them ordinances. We do not believe that they confer any special “grace”, though those who participate are certainly blessed for having done so. Christ ordained that we should participate in them, however, or lack of participation in them does not in any way diminish the fact we are saved. Sanctification is a process which ultimately culminates in our being like Christ in Heaven. We will never fully reach sanctification here on earth. But we participate out of obedience and gratitude towards our Savior. Those who neglect the ordinances are missing out on a vital part of growth as Christians. But, they are not salvific. They picture what Christ did. And, as we obey Christ in our participation, I believe we draw even closer to Him in our understanding. That may be what you all refer to as the conference of grace. But, we Baptists want to be very careful in preserving the definition of grace as God’s unmerited favor and by saying conference of grace occurs upon baptism and participating in communion (which we usually call Lord’s Supper), it can lead to a misunderstanding of what is meant (not that I am saying that you are conveying a salvific understanding to the sacraments).