Uttermost

I don't know about everyone else, but I didn't seek salvation. Salvation sought me. Salvation coaxed me along, drawing me with things that He (Salvation is a person named Jesus) knew I couldn't resist. Salvation knew me before I was even born (Ps. 139:13), and He knew what made me "tick". He used that knowledge to attract me, and to pull me to the place where He wanted me, to the place where He was waiting to finally reveal Himself to me. He didn't force me to salvation against my will, but He made the revealing so compelling, that I could not deny what was happening to me.
Salvation is not limited to a heavenly destination after death, but it is a process of transformation begun here on earth. The fullness of this transformation is the image, likeness and stature of Christ formed in each of us. It is a life-long process of "becoming" (Rom. 12:1-2). The Hebrew meaning of salvation is "save, victory, health, welfare, deliverance, prosperity, aid, preserve, defend, rescue, ample, opulent, liberty". It is also Jesus' Hebrew name.
Salvation is not a religious decision of a person, but it is a sovereign work and power of the Father, the Son, and the Holy Spirit (Rom. 1:16, 1 Pet. 1:3-5, Rev. 12:10, Rev. 19:1). All of Their great power is directed towards salvation:
Who is this that cometh...that is glorious in His apparel, travelling in the greatness of His strength? I that speak in righteousness, mighty to save."  Isa. 63:1
"Behold, the LORD's hand is not shortened, that it cannot save; neither His ear heavy (heavy, hardened, insensible, dull), that it cannot hear..."  Isa. 59:1
"O God the LORD, the strength (power, might, force, prevailing) of my salvation..." Ps. 140:7
"...Now salvation and strength, and the kingdom of God, and the power of His Christ have come..."  Rev. 12:10
Before our Father even created the earth, He and His Son made the provision for our salvation (Rev. 13:8). It was His provision and plan for us before the beginning.
As you can see, salvation is not a weak thing. It does not come out of weakness, and it does not create weakness, but it is the great power and strength of God Himself.
The authority behind salvation is the authority of our Creator, whose authority is unchallengeable:
"My sheep hear My voice, and I (Jesus) know them, and they follow Me; And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of My hand. My Father, which gave them (to) Me, is greater than all; and no man is able to pluck them out of My Father's hand."   Jn. 10:27-29
There is no other authority in heaven or on earth that can countermand the authority with which God commands forth His salvation. There is no situation or circumstance, no distance or time, that is beyond Christ's ability to save:
"Wherefore He is able also to save them to the uttermost (entirety, completely, perfectly, to the end, purpose, aim) that come unto God by Him, seeing He ever liveth to make intercession for them."  Heb. 7:25
Even those held captive in death before the manifestation of the Savior in the flesh and His work on the Cross, were not beyond Christ's ability to save:
"Therefore He says: "When He ascended on high, He led captivity (prisoner, taken away, precious stone of the priest's breastplate) captive, and gave gifts to men." (Now this, "He ascended"- what does it mean but that He also first descended into the lower parts of the earth?)"  Eph. 4:8-9 (Ps. 68:18)
"...by whom (the Spirit) also He (Jesus) went and preached to the spirits in prison."  1 Pet. 3:19
Even though it comes from the deepest part of the nature of God, which is His love (Jn. 3:16-17), and is the foundation of His plan and all of His will (Jer. 29:11), and is a miraculous mystery that can hardly be comprehended (1 Pet. 1:12), salvation does not require a complex religious ritual. Our Father makes it very easy:
"...if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised Him from the dead, thou shalt be saved."   Rom. 10:9
Even just the hearing of Jesus' salvation (Rom. 10:14), creates the basic but powerful belief needed to save, mentioned above in Rom. 10:9.
Scripture assures us that His power of salvation can be accomplished in the greatest simplicity:
"For whosoever calls upon the name of the Lord shall be saved."  Rom. 10:13, Joel 2:32
Another example of the ability of Jesus to save simply is shown in His statement:
"Behold, I stand at the door and knock. If anyone hears My voice and opens the door, I will come in to him and dine with him, and he with Me."  Rev. 3:20
Just the opening of a door. That is all a person has to do, and Jesus will handle the rest.
As much as we desire for others to receive salvation, Jesus desires it even more. Our heavenly Father gave everything, even His most Beloved, in order to make the way for His greatest power- the power of salvation.
If your heart is heavy with concern for the salvation of your loved ones, be encouraged. Let your heart know that Jesus hears your prayers, they are His prayers as well, and He is an expert at salvation. He will not fail. Remember how He led you to find Him. Remember how He saved you.
If you do not understand salvation, and have never experienced it, you can see that all you have to do is open the door of possibility to Him, and He will graciously deal with you personally, regardless of your circumstances, revealing Himself to you and teaching you all that you need to know- and the most incredible journey of your life will begin.

Our Father's plan is to save to the uttermost.

"One Thing Remains"
https://www.youtube.com/watch?v=6_KXsMCJgBQ