My mother for example, is into freemasonry, she actually believes in what she is involved with is right, but sadly it is not.
I think I get what you are describing now, so I'll explain the thoughts I got from this.
Jesus Christ is the perfect resemblance of God's nature: that is all sorts of things like wisdom, grace, love, mercy, kindness, strength, justice, righteousness etc and so on. These are qualities that naturally the human is intended to emanate in the world, so that all of creation will praise God for the wonderful life He gave us. But we know that all people naturally give in to sin, and that destroys these qualities. What we end up with in a world where people aren't gracious, kind, loving and so forth, is that the whole of creation groans and does not rejoice in love to God, for the life He gave us.
These things that destroy our godly nature, are those desires for our self. For an example, when we are envious, or greedy, or lazy or angry.
But, what is true is that nobody can convince another of the gospel of salvation if they are consumed by sin and showing such a spiritual desolation. Only when we are living gracefully, that is to say that no sin in our life is destroying those godly qualities, only then we can actually be a light of truth that shows people the way. Otherwise, when we are helping people to remove a splinter in their eye, they are distracted by the plank in ours, and they will actually not trust us to help.
.. So really, if one wants to help another gain their salvation in Christ, what they must do is sacrifice their own selfish desires - everything about their interest in the present life must become lesser than their interest in doing the right thing. This is consistent with the whole gospel message: if anyone wants to be my disciple, they must take up their cross and follow me. No person can serve two masters, you cannot serve God and mammon. Any person who gives up their home and family for my sake, will be repaid a hundred times over, and will have everlasting life. Offer up your life to God as a sweet smelling sacrifice, because that is what Jesus did for you, and this earned Him favour in God's opinion. If anyone slaps you on the cheek, offer the other to him. If someone takes from you, do not ask for it back, and give to those who ask from you. Do not be anxious, but trust in Him. Do you see those beautiful flowers? Doesn't God really care for the things He loves? Therefore, seek first the matters of God and the coming of His kingdom, and everything you need will be provided. Always rejoice in The Lord. If you remain happy while being persecuted for your good faith, then God will empower you to become a great witness to His glory.
So, it's a real calling that you are describing, to sacrifice for the sake of the salvation of others. But it isn't the next life that we are to sacrifice, it is our self-interests of the present life that we are required to make the lesser. This has real results too, that you can actually see and feel, and it is the only way to actually redeem the world from sin. This is what Jesus has done for us: He has given us the right to be called sons of God, since we are now free from the first covenant's restrictions on our conduct and forgiveness. Now, if we live in good conscience with God, knowing that we are not grieving His spirit, we have confidence that He has accepted us and we become full of life.